Overhaul infrastructure: replace GPU model with rack-centric system

Replace flat GPU buying with a realistic data center + rack pipeline:
- 4 DC tiers (small/medium/large/mega) with construction time, dual
  capacity constraints (rack slots + power budget kW), and era/research
  gating
- 10 predefined rack SKUs from consumer GPUs through custom ASICs, each
  with unique FLOPS, power draw, cost, and pipeline timings
- 6-stage procurement pipeline (order → mfg → receive → install → test
  → production) with Kanban UI, talent-influenced speed bonuses
- Test failures (5-25% base rate) reduced by cooling, ops talent, and QA
  research; auto-repair with cost and re-test cycle
- Production failures at low per-tick rate, racks sent to repair pipeline
- Cooling and redundancy upgrades per DC (reduce failure rates)
- 4 new tech tree nodes (DC Engineering II/III/IV, Quality Assurance)
- Save version bump (1→2) with migration that resets old saves
- Updated economy system to account for rack repair costs
- Redesigned Infrastructure page with pipeline Kanban, capacity bars,
  rack ordering, and DC upgrade panels

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/web/src/components/game/CompanyStatsCard.tsx

@@ -20,6 +20,7 @@ export function CompanyStatsCard({ onClose }: { onClose: () => void }) {
   const reputation = useGameStore((s) => s.reputation.score);
   const achievements = useGameStore((s) => s.achievements.unlocked.length);
   const dataCenters = useGameStore((s) => s.infrastructure.dataCenters.length);
+  const totalRacks = useGameStore((s) => s.infrastructure.totalRackCount);
 
   const eraLabel = era === 'startup' ? 'Startup' : era === 'scaleup' ? 'Scale-up' : era === 'bigtech' ? 'Big Tech' : 'AGI';
   const hours = Math.floor(totalPlayTime / 3600);
@@ -32,7 +33,7 @@ export function CompanyStatsCard({ onClose }: { onClose: () => void }) {
     `Valuation: ${formatMoney(valuation)}`,
     `Subscribers: ${formatNumber(subscribers)} | Models: ${models}`,
     `Best Model: ${bestModel.toFixed(1)}/100 | Reputation: ${reputation}/100`,
-    `Data Centers: ${dataCenters} | Achievements: ${achievements}/${ACHIEVEMENT_DEFINITIONS.length}`,
+    `Data Centers: ${dataCenters} | Racks: ${totalRacks} | Achievements: ${achievements}/${ACHIEVEMENT_DEFINITIONS.length}`,
   ].join('\n');
 
   const handleCopy = () => {

apps/web/src/pages/DashboardPage.tsx

@@ -29,7 +29,7 @@ export function DashboardPage() {
 
       {dataCenters.length === 0 && (
         <TutorialHint id="welcome">
-          Welcome to AI Tycoon! Start by building a data center in the Infrastructure tab, then buy GPUs to begin training your first AI model.
+          Welcome to AI Tycoon! Start by building a data center in the Infrastructure tab, then order racks to begin training your first AI model.
         </TutorialHint>
       )}
 

apps/web/src/pages/InfrastructurePage.tsx

@@ -1,41 +1,342 @@
 import { useState } from 'react';
-import { Plus, Server, Cpu, MapPin } from 'lucide-react';
+import { Plus, Server, MapPin, Zap, HardDrive, Wrench, ChevronDown, ChevronUp, Thermometer, Shield } from 'lucide-react';
 import { useGameStore } from '@/store';
-import { formatMoney, formatNumber, formatPercent, GPU_CONFIGS, LOCATION_CONFIGS } from '@ai-tycoon/shared';
+import {
-import type { GpuType, LocationId } from '@ai-tycoon/shared';
+  formatMoney, formatNumber, formatPercent,
+  LOCATION_CONFIGS, DC_TIER_CONFIGS, RACK_SKU_CONFIGS,
+} from '@ai-tycoon/shared';
+import type { DCTier, RackSkuId, LocationId, RackOrder, PipelineStage, Era } from '@ai-tycoon/shared';
 
-export function InfrastructurePage() {
+const ERA_ORDER: Era[] = ['startup', 'scaleup', 'bigtech', 'agi'];
-  const dataCenters = useGameStore((s) => s.infrastructure.dataCenters);
+
-  const gpuPrices = useGameStore((s) => s.infrastructure.gpuMarketPrices);
+const STAGE_LABELS: Record<PipelineStage, string> = {
+  ordered: 'Ordered',
+  manufacturing: 'Manufacturing',
+  receiving: 'Receiving',
+  installation: 'Installation',
+  testing: 'Testing',
+  repair: 'Repair',
+};
+
+const STAGE_COLORS: Record<PipelineStage, string> = {
+  ordered: 'bg-surface-600',
+  manufacturing: 'bg-blue-500',
+  receiving: 'bg-cyan-500',
+  installation: 'bg-violet-500',
+  testing: 'bg-amber-500',
+  repair: 'bg-danger',
+};
+
+function PipelineKanban() {
+  const pipeline = useGameStore((s) => s.infrastructure.rackPipeline);
+
+  if (pipeline.length === 0) return null;
+
+  const stages: PipelineStage[] = ['ordered', 'manufacturing', 'receiving', 'installation', 'testing', 'repair'];
+  const grouped = stages.map(stage => ({
+    stage,
+    orders: pipeline.filter(o => o.stage === stage),
+  }));
+
+  return (
+    <div className="bg-surface-900 border border-surface-700 rounded-xl p-4">
+      <h3 className="text-sm font-semibold text-surface-300 uppercase mb-3">Rack Pipeline</h3>
+      <div className="grid grid-cols-6 gap-2">
+        {grouped.map(({ stage, orders }) => (
+          <div key={stage}>
+            <div className="text-[10px] text-surface-400 uppercase mb-1.5 text-center">
+              {STAGE_LABELS[stage]} ({orders.length})
+            </div>
+            <div className="space-y-1.5 min-h-[60px]">
+              {orders.map(order => (
+                <PipelineCard key={order.id} order={order} />
+              ))}
+            </div>
+          </div>
+        ))}
+      </div>
+    </div>
+  );
+}
+
+function PipelineCard({ order }: { order: RackOrder }) {
+  const sku = RACK_SKU_CONFIGS[order.skuId];
+  const progress = order.stageTotal > 0 ? order.stageProgress / order.stageTotal : 0;
+
+  return (
+    <div className="bg-surface-800 border border-surface-600 rounded p-1.5 text-[11px]">
+      <div className="font-medium truncate">{sku.name}</div>
+      <div className="w-full bg-surface-700 rounded-full h-1 mt-1">
+        <div
+          className={`h-1 rounded-full ${STAGE_COLORS[order.stage]}`}
+          style={{ width: `${Math.min(100, progress * 100)}%` }}
+        />
+      </div>
+      {order.repairCount > 0 && (
+        <div className="text-danger mt-0.5 flex items-center gap-0.5">
+          <Wrench size={8} /> {order.repairCount}x
+        </div>
+      )}
+    </div>
+  );
+}
+
+function CapacityBar({ label, used, max, unit, icon: Icon }: {
+  label: string; used: number; max: number; unit: string;
+  icon: typeof HardDrive;
+}) {
+  const pct = max > 0 ? used / max : 0;
+  const color = pct > 0.9 ? 'bg-danger' : pct > 0.7 ? 'bg-amber-500' : 'bg-accent';
+
+  return (
+    <div className="flex-1">
+      <div className="flex items-center justify-between text-[11px] mb-0.5">
+        <span className="text-surface-400 flex items-center gap-1"><Icon size={12} />{label}</span>
+        <span className="text-surface-300">{formatNumber(used)}/{formatNumber(max)} {unit}</span>
+      </div>
+      <div className="w-full bg-surface-700 rounded-full h-2">
+        <div className={`h-2 rounded-full ${color} transition-all`} style={{ width: `${Math.min(100, pct * 100)}%` }} />
+      </div>
+    </div>
+  );
+}
+
+function DataCenterCard({ dcId }: { dcId: string }) {
+  const dc = useGameStore((s) => s.infrastructure.dataCenters.find(d => d.id === dcId))!;
   const money = useGameStore((s) => s.economy.money);
   const era = useGameStore((s) => s.meta.currentEra);
+  const completedResearch = useGameStore((s) => s.research.completedResearch);
+  const orderRack = useGameStore((s) => s.orderRack);
+  const upgradeDataCenter = useGameStore((s) => s.upgradeDataCenter);
+  const [expanded, setExpanded] = useState(true);
+
+  const tierConfig = DC_TIER_CONFIGS[dc.tier];
+  const currentEraIdx = ERA_ORDER.indexOf(era);
+
+  const availableSkus = Object.values(RACK_SKU_CONFIGS).filter(sku => {
+    if (ERA_ORDER.indexOf(sku.era) > currentEraIdx) return false;
+    if (sku.requiredResearch && !completedResearch.includes(sku.requiredResearch)) return false;
+    return true;
+  });
+
+  if (dc.status === 'constructing') {
+    const pct = dc.constructionTotal > 0 ? dc.constructionProgress / dc.constructionTotal : 0;
+    return (
+      <div className="bg-surface-900 border border-amber-500/30 rounded-xl p-4">
+        <div className="flex items-center justify-between mb-2">
+          <div>
+            <h3 className="font-semibold">{dc.name}</h3>
+            <div className="text-xs text-amber-400">Under Construction — {tierConfig.name}</div>
+          </div>
+          <div className="flex items-center gap-1 text-xs text-surface-400">
+            <MapPin size={12} />
+            {LOCATION_CONFIGS[dc.location].name}
+          </div>
+        </div>
+        <div className="w-full bg-surface-700 rounded-full h-3">
+          <div className="h-3 rounded-full bg-amber-500 transition-all" style={{ width: `${pct * 100}%` }} />
+        </div>
+        <div className="text-xs text-surface-400 mt-1 text-right">
+          {Math.round(pct * 100)}% — {dc.constructionTotal - dc.constructionProgress}s remaining
+        </div>
+      </div>
+    );
+  }
+
+  return (
+    <div className="bg-surface-900 border border-surface-700 rounded-xl p-4">
+      <div className="flex items-center justify-between mb-3">
+        <div>
+          <div className="flex items-center gap-2">
+            <h3 className="font-semibold text-lg">{dc.name}</h3>
+            <span className="text-[10px] px-1.5 py-0.5 rounded bg-accent/20 text-accent-light uppercase">{dc.tier}</span>
+          </div>
+          <div className="flex items-center gap-3 text-sm text-surface-400">
+            <span className="flex items-center gap-1"><MapPin size={12} />{LOCATION_CONFIGS[dc.location].name}</span>
+            <span>Uptime: {formatPercent(dc.currentUptime)}</span>
+            <span className="text-danger">Cost: {formatMoney(dc.energyCostPerTick + dc.maintenanceCostPerTick)}/s</span>
+          </div>
+        </div>
+        <button onClick={() => setExpanded(!expanded)} className="text-surface-400 hover:text-surface-200">
+          {expanded ? <ChevronUp size={18} /> : <ChevronDown size={18} />}
+        </button>
+      </div>
+
+      <div className="flex gap-4 mb-3">
+        <CapacityBar label="Slots" used={dc.usedSlots} max={tierConfig.rackSlots} unit="" icon={HardDrive} />
+        <CapacityBar label="Power" used={dc.usedPowerKW} max={tierConfig.powerBudgetKW} unit="kW" icon={Zap} />
+      </div>
+
+      {expanded && (
+        <>
+          {dc.racks.length > 0 && (
+            <div className="mb-3">
+              <h4 className="text-xs text-surface-400 uppercase mb-1.5">Production Racks ({dc.racks.length})</h4>
+              <div className="grid grid-cols-4 gap-1.5">
+                {dc.racks.map(rack => {
+                  const sku = RACK_SKU_CONFIGS[rack.skuId];
+                  return (
+                    <div key={rack.id} className={`text-[11px] rounded p-1.5 border ${
+                      rack.isHealthy
+                        ? 'bg-surface-800 border-surface-600'
+                        : 'bg-danger/10 border-danger/30'
+                    }`}>
+                      <div className="font-medium truncate">{sku.name}</div>
+                      <div className="text-surface-400">{formatNumber(sku.flopsPerRack)} FLOPS</div>
+                    </div>
+                  );
+                })}
+              </div>
+            </div>
+          )}
+
+          <div className="mb-3">
+            <h4 className="text-xs text-surface-400 uppercase mb-1.5">Order Racks</h4>
+            <div className="flex gap-2 flex-wrap">
+              {availableSkus.map(sku => {
+                const canAfford = money >= sku.baseCost;
+                const hasSlot = dc.usedSlots < tierConfig.rackSlots;
+                const hasPower = dc.usedPowerKW + sku.powerDrawKW <= tierConfig.powerBudgetKW;
+                const disabled = !canAfford || !hasSlot || !hasPower;
+
+                return (
+                  <button
+                    key={sku.id}
+                    onClick={() => orderRack(dc.id, sku.id)}
+                    disabled={disabled}
+                    className="bg-surface-800 hover:bg-surface-700 border border-surface-600 rounded-lg px-2.5 py-1.5 text-xs disabled:opacity-40 disabled:cursor-not-allowed transition-colors text-left"
+                    title={!hasSlot ? 'No slots available' : !hasPower ? 'Exceeds power budget' : ''}
+                  >
+                    <div className="font-medium">{sku.name}</div>
+                    <div className="text-surface-400">{formatNumber(sku.flopsPerRack)} FLOPS · {sku.powerDrawKW}kW · {formatMoney(sku.baseCost)}</div>
+                  </button>
+                );
+              })}
+            </div>
+          </div>
+
+          <div>
+            <h4 className="text-xs text-surface-400 uppercase mb-1.5">Upgrades</h4>
+            <div className="flex gap-2">
+              <button
+                onClick={() => upgradeDataCenter(dc.id, 'cooling')}
+                disabled={dc.coolingLevel >= 1.0 || money < tierConfig.baseCost * 0.25}
+                className="flex items-center gap-1.5 bg-surface-800 hover:bg-surface-700 border border-surface-600 rounded-lg px-3 py-2 text-xs disabled:opacity-40 disabled:cursor-not-allowed transition-colors"
+              >
+                <Thermometer size={14} />
+                Cooling Lv{Math.round(dc.coolingLevel * 10)}
+                <span className="text-surface-400">{formatMoney(tierConfig.baseCost * 0.25)}</span>
+              </button>
+              <button
+                onClick={() => upgradeDataCenter(dc.id, 'redundancy')}
+                disabled={dc.redundancyLevel >= 1.0 || money < tierConfig.baseCost * 0.25}
+                className="flex items-center gap-1.5 bg-surface-800 hover:bg-surface-700 border border-surface-600 rounded-lg px-3 py-2 text-xs disabled:opacity-40 disabled:cursor-not-allowed transition-colors"
+              >
+                <Shield size={14} />
+                Redundancy Lv{Math.round(dc.redundancyLevel * 10)}
+                <span className="text-surface-400">{formatMoney(tierConfig.baseCost * 0.25)}</span>
+              </button>
+            </div>
+          </div>
+        </>
+      )}
+    </div>
+  );
+}
+
+function BuildDCPanel({ onClose }: { onClose: () => void }) {
+  const money = useGameStore((s) => s.economy.money);
+  const era = useGameStore((s) => s.meta.currentEra);
+  const completedResearch = useGameStore((s) => s.research.completedResearch);
   const buildDataCenter = useGameStore((s) => s.buildDataCenter);
-  const buyGpu = useGameStore((s) => s.buyGpu);
 
-  const [showNewDC, setShowNewDC] = useState(false);
+  const [name, setName] = useState('');
-  const [newDCName, setNewDCName] = useState('');
+  const [location, setLocation] = useState<LocationId>('us-west');
-  const [newDCLocation, setNewDCLocation] = useState<LocationId>('us-west');
+  const [tier, setTier] = useState<DCTier>('small');
 
-  const eraOrder = ['startup', 'scaleup', 'bigtech', 'agi'];
+  const currentEraIdx = ERA_ORDER.indexOf(era);
-  const currentEraIdx = eraOrder.indexOf(era);
 
   const availableLocations = Object.values(LOCATION_CONFIGS).filter(
-    loc => eraOrder.indexOf(loc.availableAt) <= currentEraIdx,
+    loc => ERA_ORDER.indexOf(loc.availableAt) <= currentEraIdx,
   );
 
-  const availableGpus = Object.values(GPU_CONFIGS).filter(
+  const availableTiers = Object.values(DC_TIER_CONFIGS).filter(t => {
-    gpu => eraOrder.indexOf(gpu.availableAt) <= currentEraIdx,
+    if (ERA_ORDER.indexOf(t.requiredEra) > currentEraIdx) return false;
-  );
+    if (t.requiredResearch && !completedResearch.includes(t.requiredResearch)) return false;
+    return true;
+  });
 
-  const handleBuildDC = () => {
+  const tierConfig = DC_TIER_CONFIGS[tier];
-    if (!newDCName.trim()) return;
+
-    buildDataCenter(newDCName.trim(), newDCLocation);
+  const handleBuild = () => {
-    setNewDCName('');
+    if (!name.trim()) return;
-    setShowNewDC(false);
+    buildDataCenter(name.trim(), location, tier);
+    onClose();
   };
 
   return (
-    <div className="space-y-6">
+    <div className="bg-surface-900 border border-accent/30 rounded-xl p-4 space-y-4">
+      <h3 className="font-semibold">Build New Data Center</h3>
+      <div className="grid grid-cols-3 gap-4">
+        <div>
+          <label className="block text-xs text-surface-400 mb-1">Name</label>
+          <input
+            type="text"
+            value={name}
+            onChange={(e) => setName(e.target.value)}
+            placeholder="DC-West-01"
+            className="w-full bg-surface-800 border border-surface-600 rounded px-3 py-2 text-sm focus:outline-none focus:ring-2 focus:ring-accent/50"
+            autoFocus
+          />
+        </div>
+        <div>
+          <label className="block text-xs text-surface-400 mb-1">Location</label>
+          <select
+            value={location}
+            onChange={(e) => setLocation(e.target.value as LocationId)}
+            className="w-full bg-surface-800 border border-surface-600 rounded px-3 py-2 text-sm focus:outline-none focus:ring-2 focus:ring-accent/50"
+          >
+            {availableLocations.map(loc => (
+              <option key={loc.id} value={loc.id}>{loc.name} (Energy: {loc.energyCostMultiplier}x)</option>
+            ))}
+          </select>
+        </div>
+        <div>
+          <label className="block text-xs text-surface-400 mb-1">Tier</label>
+          <select
+            value={tier}
+            onChange={(e) => setTier(e.target.value as DCTier)}
+            className="w-full bg-surface-800 border border-surface-600 rounded px-3 py-2 text-sm focus:outline-none focus:ring-2 focus:ring-accent/50"
+          >
+            {availableTiers.map(t => (
+              <option key={t.tier} value={t.tier}>{t.name} ({t.rackSlots} slots, {t.powerBudgetKW}kW)</option>
+            ))}
+          </select>
+        </div>
+      </div>
+      <div className="flex items-center justify-between text-sm text-surface-400">
+        <span>Cost: {formatMoney(tierConfig.baseCost)} · Build time: {tierConfig.buildTimeTicks}s</span>
+        <div className="flex gap-2">
+          <button onClick={onClose} className="px-4 py-2 rounded text-sm text-surface-400 hover:text-surface-200">Cancel</button>
+          <button
+            onClick={handleBuild}
+            disabled={money < tierConfig.baseCost || !name.trim()}
+            className="px-4 py-2 rounded bg-accent hover:bg-accent-dark text-white text-sm disabled:opacity-50 disabled:cursor-not-allowed"
+          >
+            Build
+          </button>
+        </div>
+      </div>
+    </div>
+  );
+}
+
+export function InfrastructurePage() {
+  const dataCenters = useGameStore((s) => s.infrastructure.dataCenters);
+  const [showNewDC, setShowNewDC] = useState(false);
+
+  return (
+    <div className="space-y-4">
       <div className="flex items-center justify-between">
         <h2 className="text-2xl font-bold">Infrastructure</h2>
         <button
@@ -47,51 +348,11 @@ export function InfrastructurePage() {
         </button>
       </div>
 
-      {showNewDC && (
+      {showNewDC && <BuildDCPanel onClose={() => setShowNewDC(false)} />}
-        <div className="bg-surface-900 border border-accent/30 rounded-xl p-4 space-y-4">
-          <h3 className="font-semibold">Build New Data Center</h3>
-          <div className="grid grid-cols-2 gap-4">
-            <div>
-              <label className="block text-xs text-surface-400 mb-1">Name</label>
-              <input
-                type="text"
-                value={newDCName}
-                onChange={(e) => setNewDCName(e.target.value)}
-                placeholder="DC-West-01"
-                className="w-full bg-surface-800 border border-surface-600 rounded px-3 py-2 text-sm focus:outline-none focus:ring-2 focus:ring-accent/50"
-                autoFocus
-              />
-            </div>
-            <div>
-              <label className="block text-xs text-surface-400 mb-1">Location</label>
-              <select
-                value={newDCLocation}
-                onChange={(e) => setNewDCLocation(e.target.value as LocationId)}
-                className="w-full bg-surface-800 border border-surface-600 rounded px-3 py-2 text-sm focus:outline-none focus:ring-2 focus:ring-accent/50"
-              >
-                {availableLocations.map(loc => (
-                  <option key={loc.id} value={loc.id}>{loc.name} (Energy: {loc.energyCostMultiplier}x)</option>
-                ))}
-              </select>
-            </div>
-          </div>
-          <div className="flex items-center justify-between">
-            <span className="text-sm text-surface-400">Cost: {formatMoney(10_000)}</span>
-            <div className="flex gap-2">
-              <button onClick={() => setShowNewDC(false)} className="px-4 py-2 rounded text-sm text-surface-400 hover:text-surface-200">Cancel</button>
-              <button
-                onClick={handleBuildDC}
-                disabled={money < 10_000 || !newDCName.trim()}
-                className="px-4 py-2 rounded bg-accent hover:bg-accent-dark text-white text-sm disabled:opacity-50 disabled:cursor-not-allowed"
-              >
-                Build
-              </button>
-            </div>
-          </div>
-        </div>
-      )}
 
-      {dataCenters.length === 0 ? (
+      <PipelineKanban />
+
+      {dataCenters.length === 0 && !showNewDC ? (
         <div className="bg-surface-900 border border-surface-700 rounded-xl p-8 text-center text-surface-500">
           <Server size={48} className="mx-auto mb-4 opacity-50" />
           <p>No data centers yet. Build your first one to start hosting AI models.</p>
@@ -99,75 +360,10 @@ export function InfrastructurePage() {
       ) : (
         <div className="space-y-4">
           {dataCenters.map(dc => (
-            <div key={dc.id} className="bg-surface-900 border border-surface-700 rounded-xl p-4">
+            <DataCenterCard key={dc.id} dcId={dc.id} />
-              <div className="flex items-center justify-between mb-4">
-                <div>
-                  <h3 className="font-semibold text-lg">{dc.name}</h3>
-                  <div className="flex items-center gap-2 text-sm text-surface-400">
-                    <MapPin size={14} />
-                    {LOCATION_CONFIGS[dc.location].name}
-                  </div>
-                </div>
-                <div className="text-right text-sm">
-                  <div className="text-surface-400">Uptime: <span className="text-surface-200">{formatPercent(dc.currentUptime)}</span></div>
-                  <div className="text-surface-400">Cost: <span className="text-danger">{formatMoney(dc.energyCostPerTick + dc.maintenanceCostPerTick)}/s</span></div>
-                </div>
-              </div>
-
-              <div className="mb-4">
-                <h4 className="text-xs text-surface-400 uppercase mb-2">GPUs</h4>
-                {dc.gpus.length === 0 ? (
-                  <p className="text-sm text-surface-500">No GPUs installed</p>
-                ) : (
-                  <div className="grid grid-cols-3 gap-2">
-                    {dc.gpus.map(inv => (
-                      <div key={inv.type} className="bg-surface-800 rounded-lg p-2 text-sm">
-                        <div className="font-medium">{GPU_CONFIGS[inv.type].name}</div>
-                        <div className="text-surface-400 text-xs">
-                          {inv.healthyCount}/{inv.count} healthy · {formatNumber(inv.healthyCount * GPU_CONFIGS[inv.type].flopsPerUnit)} FLOPS
-                        </div>
-                      </div>
-                    ))}
-                  </div>
-                )}
-              </div>
-
-              <div>
-                <h4 className="text-xs text-surface-400 uppercase mb-2">Buy GPUs</h4>
-                <div className="flex gap-2 flex-wrap">
-                  {availableGpus.map(gpu => (
-                    <button
-                      key={gpu.type}
-                      onClick={() => buyGpu(dc.id, gpu.type, 1)}
-                      disabled={money < gpuPrices[gpu.type]}
-                      className="flex items-center gap-2 bg-surface-800 hover:bg-surface-700 border border-surface-600 rounded-lg px-3 py-2 text-sm disabled:opacity-40 disabled:cursor-not-allowed transition-colors"
-                    >
-                      <Cpu size={14} />
-                      {gpu.name}
-                      <span className="text-surface-400">{formatMoney(gpuPrices[gpu.type])}</span>
-                    </button>
-                  ))}
-                </div>
-              </div>
-            </div>
           ))}
         </div>
       )}
-
-      <div className="bg-surface-900 border border-surface-700 rounded-xl p-4">
-        <h3 className="text-sm font-medium text-surface-400 mb-3">GPU Market Prices</h3>
-        <div className="grid grid-cols-3 gap-3">
-          {availableGpus.map(gpu => (
-            <div key={gpu.type} className="flex items-center justify-between bg-surface-800 rounded-lg p-3">
-              <div>
-                <div className="text-sm font-medium">{gpu.name}</div>
-                <div className="text-xs text-surface-400">{formatNumber(gpu.flopsPerUnit)} FLOPS/unit</div>
-              </div>
-              <div className="text-sm font-mono">{formatMoney(gpuPrices[gpu.type])}</div>
-            </div>
-          ))}
-        </div>
-      </div>
     </div>
   );
 }

apps/web/src/store/index.ts

@@ -6,8 +6,8 @@ import type {
   ResearchState, ModelsState, MarketState,
   CompetitorState, TalentState, DataState,
   ReputationState, EventState, AchievementState,
-  DataCenter, GpuType, GpuInventory, TrainingJob,
+  DataCenter, DCTier, RackSkuId, TrainingJob,
-  ActiveResearch, EventConsequence, OwnedDataset,
+  ActiveResearch, EventConsequence, OwnedDataset, LocationId,
 } from '@ai-tycoon/shared';
 import type { FundingRoundType, OverloadPolicy, TuningPreset, ModelTuning } from '@ai-tycoon/shared';
 import {
@@ -16,7 +16,8 @@ import {
   INITIAL_RESEARCH, INITIAL_MODELS, INITIAL_MARKET,
   INITIAL_COMPETITORS, INITIAL_TALENT, INITIAL_DATA,
   INITIAL_REPUTATION, INITIAL_EVENTS, INITIAL_ACHIEVEMENTS,
-  GPU_CONFIGS,
+  DC_TIER_CONFIGS, RACK_SKU_CONFIGS,
+  PIPELINE_ORDER_BASE_TICKS, DC_UPGRADE_COST_FRACTION, DC_UPGRADE_INCREMENT,
   FUNDING_ROUNDS,
   OPEN_SOURCE_REPUTATION_BOOST,
   uuid,
@@ -48,8 +49,9 @@ interface Actions {
   setGameSpeed: (speed: GameSpeed) => void;
   togglePause: () => void;
   setTrainingAllocation: (ratio: number) => void;
-  buyGpu: (dataCenterId: string, gpuType: GpuType, count: number) => void;
+  buildDataCenter: (name: string, location: LocationId, tier: DCTier) => void;
-  buildDataCenter: (name: string, location: DataCenter['location']) => void;
+  orderRack: (dataCenterId: string, skuId: RackSkuId) => void;
+  upgradeDataCenter: (dataCenterId: string, upgrade: 'cooling' | 'redundancy') => void;
   startTraining: (job: Omit<TrainingJob, 'progressTicks'>) => void;
   deployModel: (modelId: string) => void;
   setProductPricing: (productLineId: string, field: string, value: number) => void;
@@ -146,51 +148,37 @@ export const useGameStore = create<Store>()(
         compute: { ...s.compute, trainingAllocation: ratio, inferenceAllocation: 1 - ratio },
       })),
 
-      buyGpu: (dataCenterId, gpuType, count) => set((s) => {
+      buildDataCenter: (name, location, tier) => set((s) => {
-        const price = s.infrastructure.gpuMarketPrices[gpuType] * count;
+        const tierConfig = DC_TIER_CONFIGS[tier];
-        if (s.economy.money < price) return s;
+        if (s.economy.money < tierConfig.baseCost) return s;
 
-        const dataCenters = s.infrastructure.dataCenters.map(dc => {
+        const eraOrder: Era[] = ['startup', 'scaleup', 'bigtech', 'agi'];
-          if (dc.id !== dataCenterId) return dc;
+        if (eraOrder.indexOf(s.meta.currentEra) < eraOrder.indexOf(tierConfig.requiredEra)) return s;
-          const existingIdx = dc.gpus.findIndex(g => g.type === gpuType);
+        if (tierConfig.requiredResearch && !s.research.completedResearch.includes(tierConfig.requiredResearch)) return s;
-          let gpus: GpuInventory[];
-          if (existingIdx >= 0) {
-            gpus = dc.gpus.map((g, i) =>
-              i === existingIdx
-                ? { ...g, count: g.count + count, healthyCount: g.healthyCount + count }
-                : g,
-            );
-          } else {
-            gpus = [...dc.gpus, { type: gpuType, count, healthyCount: count, failedCount: 0 }];
-          }
-          return { ...dc, gpus };
-        });
 
-        return {
+        const isFirstDC = s.infrastructure.dataCenters.length === 0;
-          economy: { ...s.economy, money: s.economy.money - price },
+        const buildTime = isFirstDC ? tierConfig.firstBuildTimeTicks : tierConfig.buildTimeTicks;
-          infrastructure: { ...s.infrastructure, dataCenters },
-        };
-      }),
-
-      buildDataCenter: (name, location) => set((s) => {
-        const buildCost = 10_000;
-        if (s.economy.money < buildCost) return s;
 
         const dc: DataCenter = {
           id: uuid(),
           name,
           location,
-          gpus: [],
+          tier,
-          maxCapacity: 100,
+          status: 'constructing',
-          coolingLevel: 0.5,
+          constructionProgress: 0,
-          redundancyLevel: 0.3,
+          constructionTotal: buildTime,
+          racks: [],
+          coolingLevel: 0,
+          redundancyLevel: 0,
           currentUptime: 1,
           energyCostPerTick: 0,
           maintenanceCostPerTick: 0,
+          usedSlots: 0,
+          usedPowerKW: 0,
         };
 
         return {
-          economy: { ...s.economy, money: s.economy.money - buildCost },
+          economy: { ...s.economy, money: s.economy.money - tierConfig.baseCost },
           infrastructure: {
             ...s.infrastructure,
             dataCenters: [...s.infrastructure.dataCenters, dc],
@@ -198,6 +186,67 @@ export const useGameStore = create<Store>()(
         };
       }),
 
+      orderRack: (dataCenterId, skuId) => set((s) => {
+        const sku = RACK_SKU_CONFIGS[skuId];
+        if (s.economy.money < sku.baseCost) return s;
+
+        const eraOrder: Era[] = ['startup', 'scaleup', 'bigtech', 'agi'];
+        if (eraOrder.indexOf(s.meta.currentEra) < eraOrder.indexOf(sku.era)) return s;
+        if (sku.requiredResearch && !s.research.completedResearch.includes(sku.requiredResearch)) return s;
+
+        const dc = s.infrastructure.dataCenters.find(d => d.id === dataCenterId);
+        if (!dc || dc.status !== 'operational') return s;
+
+        const tierConfig = DC_TIER_CONFIGS[dc.tier];
+        if (dc.usedSlots >= tierConfig.rackSlots) return s;
+        if (dc.usedPowerKW + sku.powerDrawKW > tierConfig.powerBudgetKW) return s;
+
+        const order = {
+          id: uuid(),
+          skuId,
+          dataCenterId,
+          stage: 'ordered' as const,
+          stageProgress: 0,
+          stageTotal: PIPELINE_ORDER_BASE_TICKS,
+          totalCost: sku.baseCost,
+          repairCount: 0,
+        };
+
+        return {
+          economy: { ...s.economy, money: s.economy.money - sku.baseCost },
+          infrastructure: {
+            ...s.infrastructure,
+            rackPipeline: [...s.infrastructure.rackPipeline, order],
+          },
+        };
+      }),
+
+      upgradeDataCenter: (dataCenterId, upgrade) => set((s) => {
+        const dc = s.infrastructure.dataCenters.find(d => d.id === dataCenterId);
+        if (!dc || dc.status !== 'operational') return s;
+
+        const tierConfig = DC_TIER_CONFIGS[dc.tier];
+        const cost = tierConfig.baseCost * DC_UPGRADE_COST_FRACTION;
+        if (s.economy.money < cost) return s;
+
+        const currentLevel = upgrade === 'cooling' ? dc.coolingLevel : dc.redundancyLevel;
+        if (currentLevel >= 1.0) return s;
+
+        const dataCenters = s.infrastructure.dataCenters.map(d => {
+          if (d.id !== dataCenterId) return d;
+          return {
+            ...d,
+            [upgrade === 'cooling' ? 'coolingLevel' : 'redundancyLevel']:
+              Math.min(1.0, currentLevel + DC_UPGRADE_INCREMENT),
+          };
+        });
+
+        return {
+          economy: { ...s.economy, money: s.economy.money - cost },
+          infrastructure: { ...s.infrastructure, dataCenters },
+        };
+      }),
+
       startTraining: (job) => set((s) => ({
         models: {
           ...s.models,
@@ -419,10 +468,28 @@ export const useGameStore = create<Store>()(
     }),
     {
       name: 'ai-tycoon-save',
+      version: SAVE_VERSION,
       partialize: (state) => {
         const { activePage, notifications, ...rest } = state;
         return rest;
       },
+      migrate: (_persisted, version) => {
+        if (version < SAVE_VERSION) {
+          return {
+            ...initialGameState,
+            activePage: 'dashboard' as const,
+            notifications: [{
+              id: uuid(),
+              title: 'Save Reset',
+              message: 'Your save was reset due to a major infrastructure overhaul. Enjoy the new rack-based system!',
+              type: 'info' as const,
+              tick: 0,
+              read: false,
+            }],
+          } as unknown as Store;
+        }
+        return _persisted as Store;
+      },
     },
   ),
 );

packages/game-engine/src/data/achievements.ts

@@ -79,11 +79,11 @@ export const ACHIEVEMENT_DEFINITIONS: AchievementDefinition[] = [
     condition: { field: 'meta._eraIndex', operator: 'gte', value: 3 },
   },
   {
-    id: 'gpu-hoarder',
+    id: 'rack-hoarder',
-    name: 'GPU Hoarder',
+    name: 'Rack Hoarder',
-    description: 'Own 100 or more GPUs across all data centers.',
+    description: 'Have 50 or more production racks across all data centers.',
     icon: 'Cpu',
-    condition: { field: 'infrastructure._totalGpuCount', operator: 'gte', value: 100 },
+    condition: { field: 'infrastructure.totalRackCount', operator: 'gte', value: 50 },
   },
   {
     id: 'research-pioneer',

packages/game-engine/src/data/techTree.ts

@@ -25,32 +25,32 @@ export const TECH_TREE: ResearchNode[] = [
   {
     id: 'advanced-gpu-arch',
     name: 'Advanced GPU Architecture',
-    description: 'Unlocks procurement of NVIDIA A100 datacenter GPUs.',
+    description: 'Unlocks procurement of NVIDIA A100 rack configurations.',
     era: 'startup',
     category: 'infrastructure',
     prerequisites: [],
     cost: { researchPoints: 0, compute: 10, ticks: 90 },
-    effects: [{ type: 'unlock_gpu', target: 'a100', value: 1 }],
+    effects: [{ type: 'unlock_rack', target: 'a100', value: 1 }],
   },
   {
     id: 'next-gen-gpu',
     name: 'Next-Gen GPU Architecture',
-    description: 'Unlocks procurement of NVIDIA H100 GPUs.',
+    description: 'Unlocks procurement of NVIDIA H100 rack configurations.',
     era: 'scaleup',
     category: 'infrastructure',
     prerequisites: ['advanced-gpu-arch'],
     cost: { researchPoints: 2, compute: 40, ticks: 240 },
-    effects: [{ type: 'unlock_gpu', target: 'h100', value: 1 }],
+    effects: [{ type: 'unlock_rack', target: 'h100', value: 1 }],
   },
   {
     id: 'frontier-compute',
     name: 'Frontier Compute',
-    description: 'Unlocks procurement of NVIDIA B200 GPUs.',
+    description: 'Unlocks procurement of NVIDIA B200 rack configurations.',
     era: 'bigtech',
     category: 'infrastructure',
     prerequisites: ['next-gen-gpu'],
     cost: { researchPoints: 5, compute: 200, ticks: 480 },
-    effects: [{ type: 'unlock_gpu', target: 'b200', value: 1 }],
+    effects: [{ type: 'unlock_rack', target: 'b200', value: 1 }],
   },
   {
     id: 'custom-silicon',
@@ -60,7 +60,47 @@ export const TECH_TREE: ResearchNode[] = [
     category: 'infrastructure',
     prerequisites: ['frontier-compute'],
     cost: { researchPoints: 10, compute: 500, ticks: 900 },
-    effects: [{ type: 'unlock_gpu', target: 'custom', value: 1 }],
+    effects: [{ type: 'unlock_rack', target: 'custom', value: 1 }],
+  },
+  {
+    id: 'dc-engineering-ii',
+    name: 'DC Engineering II',
+    description: 'Advanced facility design unlocks Medium data centers (30 slots, 200kW).',
+    era: 'startup',
+    category: 'infrastructure',
+    prerequisites: ['advanced-cooling'],
+    cost: { researchPoints: 1, compute: 15, ticks: 120 },
+    effects: [{ type: 'unlock_dc_tier', target: 'medium', value: 1 }],
+  },
+  {
+    id: 'dc-engineering-iii',
+    name: 'DC Engineering III',
+    description: 'Large-scale facility design unlocks Large data centers (60 slots, 500kW).',
+    era: 'scaleup',
+    category: 'infrastructure',
+    prerequisites: ['dc-engineering-ii'],
+    cost: { researchPoints: 3, compute: 60, ticks: 300 },
+    effects: [{ type: 'unlock_dc_tier', target: 'large', value: 1 }],
+  },
+  {
+    id: 'dc-engineering-iv',
+    name: 'DC Engineering IV',
+    description: 'Mega-scale campus design unlocks Mega data centers (120 slots, 1200kW).',
+    era: 'bigtech',
+    category: 'infrastructure',
+    prerequisites: ['dc-engineering-iii'],
+    cost: { researchPoints: 6, compute: 150, ticks: 600 },
+    effects: [{ type: 'unlock_dc_tier', target: 'mega', value: 1 }],
+  },
+  {
+    id: 'quality-assurance',
+    name: 'Quality Assurance',
+    description: 'Advanced QA processes reduce rack test failure rate by 25%.',
+    era: 'startup',
+    category: 'infrastructure',
+    prerequisites: ['redundancy-protocols'],
+    cost: { researchPoints: 1, compute: 10, ticks: 90 },
+    effects: [{ type: 'cost_reduction', target: 'test_failure_rate', value: 0.25 }],
   },
   {
     id: 'distributed-training',

packages/game-engine/src/systems/achievementSystem.ts

@@ -10,12 +10,6 @@ const ERA_INDEX: Record<string, number> = { startup: 0, scaleup: 1, bigtech: 2,
 function getFieldValue(state: GameState, field: string): number {
   if (field === 'meta._eraIndex') return ERA_INDEX[state.meta.currentEra] ?? 0;
   if (field === 'meta._deployedModelCount') return state.models.trainedModels.filter(m => m.isDeployed).length;
-  if (field === 'infrastructure._totalGpuCount') {
-    return state.infrastructure.dataCenters.reduce(
-      (sum, dc) => sum + dc.gpus.reduce((s, g) => s + g.count, 0), 0,
-    );
-  }
-
   const parts = field.split('.');
   let current: unknown = state;
   for (const part of parts) {

packages/game-engine/src/systems/economySystem.ts

@@ -6,6 +6,7 @@ export function processEconomy(
   state: GameState,
   market: MarketTickResult,
   infrastructure: InfrastructureState,
+  extraCosts: number = 0,
 ): EconomyState {
   const revenue = market.apiRevenue + market.subscriptionRevenue;
 
@@ -20,7 +21,7 @@ export function processEconomy(
   const eraIdx = ['startup', 'scaleup', 'bigtech', 'agi'].indexOf(state.meta.currentEra);
   const complianceCost = bestCapability > 30 ? bestCapability * REGULATION_COMPLIANCE_PER_CAPABILITY * (1 + eraIdx * 0.5) / 100 : 0;
 
-  const expenses = infraExpenses + talentExpenses + dataExpenses + complianceCost;
+  const expenses = infraExpenses + talentExpenses + dataExpenses + complianceCost + extraCosts;
 
   const money = state.economy.money + revenue - expenses;
 

packages/game-engine/src/systems/infrastructureSystem.ts

@@ -1,72 +1,275 @@
-import type { GameState, InfrastructureState } from '@ai-tycoon/shared';
+import type { GameState, InfrastructureState, DataCenter, RackOrder, Rack, PipelineStage } from '@ai-tycoon/shared';
 import {
-  GPU_CONFIGS,
   LOCATION_CONFIGS,
-  GPU_PRICE_VOLATILITY,
+  RACK_SKU_CONFIGS,
-  GPU_FAILURE_RATE_BASE,
+  DC_TIER_CONFIGS,
-  REDUNDANCY_FAILURE_REDUCTION,
   BASE_ENERGY_COST_PER_FLOP,
-  BASE_MAINTENANCE_PER_GPU,
+  BASE_MAINTENANCE_PER_RACK,
+  COOLING_FAILURE_REDUCTION,
+  REDUNDANCY_FAILURE_REDUCTION,
+  RACK_REPAIR_BASE_TICKS,
 } from '@ai-tycoon/shared';
-import type { GpuType } from '@ai-tycoon/shared';
+import type { TickNotification } from '../tick';
 
-export function processInfrastructure(state: GameState): InfrastructureState {
+export interface InfraTickResult {
-  const dataCenters = state.infrastructure.dataCenters.map(dc => {
+  infrastructure: InfrastructureState;
-    const location = LOCATION_CONFIGS[dc.location];
+  notifications: TickNotification[];
+  repairCosts: number;
+}
 
-    const gpus = dc.gpus.map(inv => {
+const PIPELINE_ADVANCE_ORDER: PipelineStage[] = [
-      const failureRate = GPU_FAILURE_RATE_BASE * (1 - dc.redundancyLevel * REDUNDANCY_FAILURE_REDUCTION);
+  'ordered', 'manufacturing', 'receiving', 'installation', 'testing',
-      let newFailed = inv.failedCount;
+];
-      for (let i = 0; i < inv.healthyCount; i++) {
-        if (Math.random() < failureRate) newFailed++;
-      }
-      const healthyCount = Math.max(0, inv.count - newFailed);
-      return { ...inv, healthyCount, failedCount: newFailed };
-    });
 
-    let totalFlops = 0;
+function nextStage(stage: PipelineStage): PipelineStage | 'production' {
-    let totalPower = 0;
+  const idx = PIPELINE_ADVANCE_ORDER.indexOf(stage);
-    let totalGpuCount = 0;
+  if (idx === -1 || idx === PIPELINE_ADVANCE_ORDER.length - 1) return 'production';
-    for (const inv of gpus) {
+  return PIPELINE_ADVANCE_ORDER[idx + 1];
-      const config = GPU_CONFIGS[inv.type];
+}
-      totalFlops += inv.healthyCount * config.flopsPerUnit;
+
-      totalPower += inv.healthyCount * config.basePowerDraw;
+function stageTotal(stage: PipelineStage, order: RackOrder): number {
-      totalGpuCount += inv.count;
+  const sku = RACK_SKU_CONFIGS[order.skuId];
+  const timings = sku.pipelineTimeTicks;
+  switch (stage) {
+    case 'manufacturing': return timings.manufacturing;
+    case 'receiving': return timings.receiving;
+    case 'installation': return timings.installation;
+    case 'testing': return timings.testing;
+    case 'repair': return RACK_REPAIR_BASE_TICKS;
+    default: return 0;
+  }
+}
+
+function stageSpeed(stage: PipelineStage, engEff: number, opsEff: number): number {
+  switch (stage) {
+    case 'manufacturing': return 1 + engEff * 0.1;
+    case 'installation':
+    case 'testing': return 1 + opsEff * 0.1;
+    case 'repair': return 1 + opsEff * 0.05;
+    default: return 1;
+  }
+}
+
+export function processInfrastructure(state: GameState): InfraTickResult {
+  const notifications: TickNotification[] = [];
+  let repairCosts = 0;
+
+  const engEff = state.talent.departments.engineering.effectiveness;
+  const opsEff = state.talent.departments.operations.effectiveness;
+
+  const qaResearchBonus = state.research.completedResearch.includes('quality-assurance') ? 0.25 : 0;
+
+  // --- Phase 1: Advance DC Construction ---
+  const dataCenters: DataCenter[] = state.infrastructure.dataCenters.map(dc => {
+    if (dc.status !== 'constructing') return { ...dc };
+
+    const newProgress = dc.constructionProgress + 1;
+    if (newProgress >= dc.constructionTotal) {
+      notifications.push({
+        title: 'Data Center Online',
+        message: `${dc.name} is now operational!`,
+        type: 'success',
+      });
+      return { ...dc, constructionProgress: dc.constructionTotal, status: 'operational' as const };
     }
-
+    return { ...dc, constructionProgress: newProgress };
-    const energyCostPerTick = totalPower * BASE_ENERGY_COST_PER_FLOP * location.energyCostMultiplier;
-    const maintenanceCostPerTick = totalGpuCount * BASE_MAINTENANCE_PER_GPU;
-    const currentUptime = totalGpuCount > 0
-      ? gpus.reduce((s, inv) => s + inv.healthyCount, 0) / totalGpuCount
-      : 1;
-
-    return { ...dc, gpus, energyCostPerTick, maintenanceCostPerTick, currentUptime };
   });
 
-  const gpuMarketPrices = { ...state.infrastructure.gpuMarketPrices };
+  // --- Phase 2: Advance Rack Pipeline ---
-  for (const gpuType of Object.keys(gpuMarketPrices) as GpuType[]) {
+  const rackPipeline: RackOrder[] = [];
-    const basePrice = GPU_CONFIGS[gpuType].basePrice;
+  const newRacks: Rack[] = [];
-    const variation = (Math.random() - 0.5) * 2 * GPU_PRICE_VOLATILITY;
+
-    const currentPrice = gpuMarketPrices[gpuType];
+  for (const order of state.infrastructure.rackPipeline) {
-    const newPrice = currentPrice * (1 + variation);
+    const speed = stageSpeed(order.stage, engEff, opsEff);
-    gpuMarketPrices[gpuType] = Math.max(basePrice * 0.7, Math.min(basePrice * 1.5, newPrice));
+    const newProgress = order.stageProgress + speed;
+
+    if (newProgress < order.stageTotal) {
+      rackPipeline.push({ ...order, stageProgress: newProgress });
+      continue;
+    }
+
+    if (order.stage === 'repair') {
+      const total = stageTotal('testing', order);
+      rackPipeline.push({
+        ...order,
+        stage: 'testing',
+        stageProgress: 0,
+        stageTotal: total,
+      });
+      continue;
+    }
+
+    const next = nextStage(order.stage);
+
+    if (next === 'production') {
+      const sku = RACK_SKU_CONFIGS[order.skuId];
+      const dc = dataCenters.find(d => d.id === order.dataCenterId);
+      const cooling = dc?.coolingLevel ?? 0;
+
+      const effectiveFailRate = sku.testFailureRate
+        * (1 - cooling * COOLING_FAILURE_REDUCTION)
+        * (1 - opsEff * 0.2)
+        * (1 - qaResearchBonus);
+
+      if (Math.random() < effectiveFailRate) {
+        const repairCost = sku.baseCost * sku.repairCostFraction;
+        repairCosts += repairCost;
+        rackPipeline.push({
+          ...order,
+          stage: 'repair',
+          stageProgress: 0,
+          stageTotal: RACK_REPAIR_BASE_TICKS,
+          repairCount: order.repairCount + 1,
+        });
+        notifications.push({
+          title: 'Rack Failed Testing',
+          message: `${sku.name} rack failed QA (attempt ${order.repairCount + 1}). Repair cost: $${repairCost.toLocaleString()}`,
+          type: 'warning',
+        });
+      } else {
+        newRacks.push({
+          id: order.id,
+          skuId: order.skuId,
+          dataCenterId: order.dataCenterId,
+          isHealthy: true,
+        });
+        notifications.push({
+          title: 'Rack Online',
+          message: `${sku.name} rack is now in production at ${dc?.name ?? 'data center'}.`,
+          type: 'success',
+        });
+      }
+    } else {
+      const total = stageTotal(next, order);
+      rackPipeline.push({
+        ...order,
+        stage: next,
+        stageProgress: 0,
+        stageTotal: total,
+      });
+    }
   }
 
+  // Add newly completed racks to their data centers
+  for (const rack of newRacks) {
+    const dcIdx = dataCenters.findIndex(d => d.id === rack.dataCenterId);
+    if (dcIdx !== -1) {
+      dataCenters[dcIdx] = {
+        ...dataCenters[dcIdx],
+        racks: [...dataCenters[dcIdx].racks, rack],
+      };
+    }
+  }
+
+  // --- Phase 3: Production Failures ---
+  for (let dcIdx = 0; dcIdx < dataCenters.length; dcIdx++) {
+    const dc = dataCenters[dcIdx];
+    if (dc.status !== 'operational') continue;
+
+    const updatedRacks: Rack[] = [];
+    for (const rack of dc.racks) {
+      if (!rack.isHealthy) {
+        updatedRacks.push(rack);
+        continue;
+      }
+
+      const sku = RACK_SKU_CONFIGS[rack.skuId];
+      const effectiveRate = sku.productionFailureRate
+        * (1 - dc.coolingLevel * COOLING_FAILURE_REDUCTION)
+        * (1 - dc.redundancyLevel * REDUNDANCY_FAILURE_REDUCTION);
+
+      if (Math.random() < effectiveRate) {
+        updatedRacks.push({ ...rack, isHealthy: false });
+        const repairCost = sku.baseCost * sku.repairCostFraction;
+        repairCosts += repairCost;
+
+        rackPipeline.push({
+          id: rack.id,
+          skuId: rack.skuId,
+          dataCenterId: dc.id,
+          stage: 'repair',
+          stageProgress: 0,
+          stageTotal: RACK_REPAIR_BASE_TICKS,
+          totalCost: repairCost,
+          repairCount: 0,
+        });
+
+        notifications.push({
+          title: 'Rack Failure',
+          message: `${sku.name} rack failed in ${dc.name}. Sent for repair.`,
+          type: 'danger',
+        });
+      } else {
+        updatedRacks.push(rack);
+      }
+    }
+
+    // Remove failed racks from the DC (they're now in the repair pipeline)
+    dataCenters[dcIdx] = {
+      ...dc,
+      racks: updatedRacks.filter(r => r.isHealthy),
+    };
+  }
+
+  // --- Phase 4: Compute Aggregates ---
   let totalFlops = 0;
   let totalUptime = 0;
-  let dcCount = 0;
+  let totalRackCount = 0;
-  for (const dc of dataCenters) {
+  let dcWithRacks = 0;
-    for (const inv of dc.gpus) {
+
-      totalFlops += inv.healthyCount * GPU_CONFIGS[inv.type].flopsPerUnit;
+  for (let dcIdx = 0; dcIdx < dataCenters.length; dcIdx++) {
+    const dc = dataCenters[dcIdx];
+    if (dc.status !== 'operational') continue;
+
+    const location = LOCATION_CONFIGS[dc.location];
+    const tierConfig = DC_TIER_CONFIGS[dc.tier];
+
+    let dcFlops = 0;
+    let usedPowerKW = 0;
+    const healthyCount = dc.racks.length;
+    const totalInDc = dc.racks.length;
+
+    for (const rack of dc.racks) {
+      const sku = RACK_SKU_CONFIGS[rack.skuId];
+      dcFlops += sku.flopsPerRack;
+      usedPowerKW += sku.powerDrawKW;
     }
-    totalUptime += dc.currentUptime;
+
-    dcCount++;
+    const pipelineRacksForDc = rackPipeline.filter(o => o.dataCenterId === dc.id).length;
+    const usedSlots = totalInDc + pipelineRacksForDc;
+
+    const energyCostPerTick = (tierConfig.baseEnergyCostPerTick + usedPowerKW * BASE_ENERGY_COST_PER_FLOP)
+      * location.energyCostMultiplier;
+    const maintenanceCostPerTick = totalInDc * BASE_MAINTENANCE_PER_RACK;
+
+    const currentUptime = totalInDc > 0 ? healthyCount / totalInDc : 1;
+
+    totalFlops += dcFlops;
+    totalRackCount += totalInDc;
+    if (totalInDc > 0) {
+      totalUptime += currentUptime;
+      dcWithRacks++;
+    }
+
+    dataCenters[dcIdx] = {
+      ...dataCenters[dcIdx],
+      usedSlots,
+      usedPowerKW,
+      energyCostPerTick,
+      maintenanceCostPerTick,
+      currentUptime,
+    };
   }
 
   return {
-    dataCenters,
+    infrastructure: {
-    gpuMarketPrices,
+      dataCenters,
-    totalFlops,
+      rackPipeline,
-    totalUptime: dcCount > 0 ? totalUptime / dcCount : 1,
+      totalFlops,
+      totalUptime: dcWithRacks > 0 ? totalUptime / dcWithRacks : 1,
+      totalRackCount,
+    },
+    notifications,
+    repairCosts,
   };
 }

packages/game-engine/src/tick.ts

@@ -39,7 +39,9 @@ export function setAchievementDefinitions(defs: AchievementDefinition[]) {
 export function processTick(state: GameState): Partial<GameState> {
   const notifications: TickNotification[] = [];
 
-  const infrastructure = processInfrastructure(state);
+  const infraResult = processInfrastructure(state);
+  const infrastructure = infraResult.infrastructure;
+  notifications.push(...infraResult.notifications);
 
   const stateWithInfra = { ...state, infrastructure };
   const modelResult = processModels(stateWithInfra);
@@ -82,7 +84,7 @@ export function processTick(state: GameState): Partial<GameState> {
       type: 'danger',
     });
   }
-  const economy = processEconomy(stateWithTalent, market, infrastructure);
+  const economy = processEconomy(stateWithTalent, market, infrastructure, infraResult.repairCosts);
   const data = processData(stateWithTalent);
   const competitors = processCompetitors(stateWithTalent);
 

packages/shared/src/constants/gameBalance.ts

@@ -1,3 +1,5 @@
+import type { DCTier, DCTierConfig, RackSkuId, RackSkuConfig } from '../types/infrastructure';
+
 export const TICK_INTERVAL_MS = 1000;
 export const MAX_OFFLINE_TICKS = 86_400;
 export const OFFLINE_EFFICIENCY = 0.8;
@@ -10,7 +12,6 @@ export const MAX_REPUTATION_HISTORY = 500;
 
 export const STARTING_MONEY = 50_000;
 export const BASE_ENERGY_COST_PER_FLOP = 0.001;
-export const BASE_MAINTENANCE_PER_GPU = 0.005;
 
 export const TRAINING_BASE_TICKS = 120;
 export const TRAINING_COMPUTE_MULTIPLIER = 0.8;
@@ -37,9 +38,213 @@ export const ERA_THRESHOLDS = {
   agi: { revenue: 100_000_000, capability: 90, reputation: 70 },
 };
 
-export const GPU_PRICE_VOLATILITY = 0.02;
+// --- Data Center Tier Configs ---
-export const GPU_FAILURE_RATE_BASE = 0.0001;
+
+export const DC_TIER_CONFIGS: Record<DCTier, DCTierConfig> = {
+  small: {
+    tier: 'small',
+    name: 'Small Data Center',
+    rackSlots: 12,
+    powerBudgetKW: 60,
+    baseCost: 10_000,
+    buildTimeTicks: 300,
+    firstBuildTimeTicks: 10,
+    requiredEra: 'startup',
+    requiredResearch: null,
+    baseEnergyCostPerTick: 5,
+  },
+  medium: {
+    tier: 'medium',
+    name: 'Medium Data Center',
+    rackSlots: 30,
+    powerBudgetKW: 200,
+    baseCost: 50_000,
+    buildTimeTicks: 900,
+    firstBuildTimeTicks: 900,
+    requiredEra: 'scaleup',
+    requiredResearch: 'dc-engineering-ii',
+    baseEnergyCostPerTick: 15,
+  },
+  large: {
+    tier: 'large',
+    name: 'Large Data Center',
+    rackSlots: 60,
+    powerBudgetKW: 500,
+    baseCost: 200_000,
+    buildTimeTicks: 1800,
+    firstBuildTimeTicks: 1800,
+    requiredEra: 'bigtech',
+    requiredResearch: 'dc-engineering-iii',
+    baseEnergyCostPerTick: 40,
+  },
+  mega: {
+    tier: 'mega',
+    name: 'Mega Data Center',
+    rackSlots: 120,
+    powerBudgetKW: 1200,
+    baseCost: 1_000_000,
+    buildTimeTicks: 3600,
+    firstBuildTimeTicks: 3600,
+    requiredEra: 'agi',
+    requiredResearch: 'dc-engineering-iv',
+    baseEnergyCostPerTick: 100,
+  },
+};
+
+// --- Rack SKU Configs ---
+
+export const RACK_SKU_CONFIGS: Record<RackSkuId, RackSkuConfig> = {
+  'consumer-x4': {
+    id: 'consumer-x4',
+    name: 'Consumer GPU x4',
+    era: 'startup',
+    gpuCount: 4,
+    flopsPerRack: 4,
+    powerDrawKW: 0.4,
+    baseCost: 3_200,
+    requiredResearch: null,
+    pipelineTimeTicks: { manufacturing: 20, receiving: 10, installation: 15, testing: 15 },
+    testFailureRate: 0.05,
+    productionFailureRate: 0.0002,
+    repairCostFraction: 0.10,
+  },
+  't4-x4': {
+    id: 't4-x4',
+    name: 'NVIDIA T4 x4',
+    era: 'startup',
+    gpuCount: 4,
+    flopsPerRack: 32,
+    powerDrawKW: 1.2,
+    baseCost: 20_000,
+    requiredResearch: null,
+    pipelineTimeTicks: { manufacturing: 30, receiving: 15, installation: 25, testing: 20 },
+    testFailureRate: 0.07,
+    productionFailureRate: 0.0003,
+    repairCostFraction: 0.12,
+  },
+  't4-x8': {
+    id: 't4-x8',
+    name: 'NVIDIA T4 x8',
+    era: 'scaleup',
+    gpuCount: 8,
+    flopsPerRack: 64,
+    powerDrawKW: 2.4,
+    baseCost: 38_000,
+    requiredResearch: null,
+    pipelineTimeTicks: { manufacturing: 40, receiving: 20, installation: 30, testing: 30 },
+    testFailureRate: 0.08,
+    productionFailureRate: 0.0003,
+    repairCostFraction: 0.12,
+  },
+  'a100-x4': {
+    id: 'a100-x4',
+    name: 'NVIDIA A100 x4',
+    era: 'scaleup',
+    gpuCount: 4,
+    flopsPerRack: 160,
+    powerDrawKW: 4.0,
+    baseCost: 60_000,
+    requiredResearch: 'advanced-gpu-arch',
+    pipelineTimeTicks: { manufacturing: 60, receiving: 25, installation: 50, testing: 45 },
+    testFailureRate: 0.10,
+    productionFailureRate: 0.0004,
+    repairCostFraction: 0.15,
+  },
+  'a100-x8': {
+    id: 'a100-x8',
+    name: 'NVIDIA A100 x8',
+    era: 'scaleup',
+    gpuCount: 8,
+    flopsPerRack: 320,
+    powerDrawKW: 8.0,
+    baseCost: 115_000,
+    requiredResearch: 'advanced-gpu-arch',
+    pipelineTimeTicks: { manufacturing: 70, receiving: 30, installation: 55, testing: 55 },
+    testFailureRate: 0.12,
+    productionFailureRate: 0.0004,
+    repairCostFraction: 0.15,
+  },
+  'h100-x4': {
+    id: 'h100-x4',
+    name: 'NVIDIA H100 x4',
+    era: 'bigtech',
+    gpuCount: 4,
+    flopsPerRack: 480,
+    powerDrawKW: 5.6,
+    baseCost: 140_000,
+    requiredResearch: 'next-gen-gpu',
+    pipelineTimeTicks: { manufacturing: 80, receiving: 30, installation: 65, testing: 65 },
+    testFailureRate: 0.15,
+    productionFailureRate: 0.0005,
+    repairCostFraction: 0.18,
+  },
+  'h100-x8': {
+    id: 'h100-x8',
+    name: 'NVIDIA H100 x8',
+    era: 'bigtech',
+    gpuCount: 8,
+    flopsPerRack: 960,
+    powerDrawKW: 11.2,
+    baseCost: 270_000,
+    requiredResearch: 'next-gen-gpu',
+    pipelineTimeTicks: { manufacturing: 90, receiving: 35, installation: 75, testing: 80 },
+    testFailureRate: 0.18,
+    productionFailureRate: 0.0005,
+    repairCostFraction: 0.18,
+  },
+  'b200-x4': {
+    id: 'b200-x4',
+    name: 'NVIDIA B200 x4',
+    era: 'bigtech',
+    gpuCount: 4,
+    flopsPerRack: 1600,
+    powerDrawKW: 8.0,
+    baseCost: 200_000,
+    requiredResearch: 'frontier-compute',
+    pipelineTimeTicks: { manufacturing: 100, receiving: 40, installation: 80, testing: 80 },
+    testFailureRate: 0.20,
+    productionFailureRate: 0.0006,
+    repairCostFraction: 0.20,
+  },
+  'b200-x8': {
+    id: 'b200-x8',
+    name: 'NVIDIA B200 x8',
+    era: 'agi',
+    gpuCount: 8,
+    flopsPerRack: 3200,
+    powerDrawKW: 16.0,
+    baseCost: 380_000,
+    requiredResearch: 'frontier-compute',
+    pipelineTimeTicks: { manufacturing: 120, receiving: 45, installation: 95, testing: 100 },
+    testFailureRate: 0.22,
+    productionFailureRate: 0.0006,
+    repairCostFraction: 0.20,
+  },
+  'custom-x8': {
+    id: 'custom-x8',
+    name: 'Custom ASIC x8',
+    era: 'agi',
+    gpuCount: 8,
+    flopsPerRack: 6400,
+    powerDrawKW: 20.0,
+    baseCost: 640_000,
+    requiredResearch: 'custom-silicon',
+    pipelineTimeTicks: { manufacturing: 140, receiving: 50, installation: 100, testing: 110 },
+    testFailureRate: 0.25,
+    productionFailureRate: 0.0008,
+    repairCostFraction: 0.20,
+  },
+};
+
+// --- Pipeline & Infrastructure Constants ---
+
+export const PIPELINE_ORDER_BASE_TICKS = 15;
+export const RACK_REPAIR_BASE_TICKS = 30;
+export const BASE_MAINTENANCE_PER_RACK = 0.02;
+export const COOLING_FAILURE_REDUCTION = 0.5;
 export const REDUNDANCY_FAILURE_REDUCTION = 0.5;
+export const DC_UPGRADE_COST_FRACTION = 0.25;
+export const DC_UPGRADE_INCREMENT = 0.1;
 
 export const FUNDING_ROUNDS = {
   seed: { amount: 100_000, dilution: 0.10, requirements: { minRevenue: 100, minUsers: 0, minReputation: 0 } },

packages/shared/src/types/gameState.ts

@@ -60,4 +60,4 @@ export const INITIAL_SETTINGS: GameSettings = {
   sfxVolume: 0.7,
 };
 
-export const SAVE_VERSION = 1;
+export const SAVE_VERSION = 2;

packages/shared/src/types/infrastructure.ts

@@ -1,33 +1,112 @@
 import type { Era } from './gameState';
 
-export interface InfrastructureState {
+// --- Data Center ---
-  dataCenters: DataCenter[];
+
-  gpuMarketPrices: Record<GpuType, number>;
+export type DCTier = 'small' | 'medium' | 'large' | 'mega';
-  totalFlops: number;
+export type DCStatus = 'constructing' | 'operational';
-  totalUptime: number;
+
+export interface DCTierConfig {
+  tier: DCTier;
+  name: string;
+  rackSlots: number;
+  powerBudgetKW: number;
+  baseCost: number;
+  buildTimeTicks: number;
+  firstBuildTimeTicks: number;
+  requiredEra: Era;
+  requiredResearch: string | null;
+  baseEnergyCostPerTick: number;
 }
 
 export interface DataCenter {
   id: string;
   name: string;
   location: LocationId;
-  gpus: GpuInventory[];
+  tier: DCTier;
-  maxCapacity: number;
+  status: DCStatus;
+  constructionProgress: number;
+  constructionTotal: number;
+  racks: Rack[];
   coolingLevel: number;
   redundancyLevel: number;
   currentUptime: number;
   energyCostPerTick: number;
   maintenanceCostPerTick: number;
+  usedSlots: number;
+  usedPowerKW: number;
 }
 
-export interface GpuInventory {
+// --- Racks ---
-  type: GpuType;
+
-  count: number;
+export type RackSkuId =
-  healthyCount: number;
+  | 'consumer-x4' | 't4-x4' | 't4-x8'
-  failedCount: number;
+  | 'a100-x4' | 'a100-x8'
+  | 'h100-x4' | 'h100-x8'
+  | 'b200-x4' | 'b200-x8' | 'custom-x8';
+
+export type PipelineStage =
+  | 'ordered' | 'manufacturing' | 'receiving'
+  | 'installation' | 'testing' | 'repair';
+
+export interface PipelineTimings {
+  manufacturing: number;
+  receiving: number;
+  installation: number;
+  testing: number;
 }
 
-export type GpuType = 'consumer' | 't4' | 'a100' | 'h100' | 'b200' | 'custom';
+export interface RackSkuConfig {
+  id: RackSkuId;
+  name: string;
+  era: Era;
+  gpuCount: number;
+  flopsPerRack: number;
+  powerDrawKW: number;
+  baseCost: number;
+  requiredResearch: string | null;
+  pipelineTimeTicks: PipelineTimings;
+  testFailureRate: number;
+  productionFailureRate: number;
+  repairCostFraction: number;
+}
+
+export interface Rack {
+  id: string;
+  skuId: RackSkuId;
+  dataCenterId: string;
+  isHealthy: boolean;
+}
+
+export interface RackOrder {
+  id: string;
+  skuId: RackSkuId;
+  dataCenterId: string;
+  stage: PipelineStage;
+  stageProgress: number;
+  stageTotal: number;
+  totalCost: number;
+  repairCount: number;
+}
+
+// --- Infrastructure State ---
+
+export interface InfrastructureState {
+  dataCenters: DataCenter[];
+  rackPipeline: RackOrder[];
+  totalFlops: number;
+  totalUptime: number;
+  totalRackCount: number;
+}
+
+export const INITIAL_INFRASTRUCTURE: InfrastructureState = {
+  dataCenters: [],
+  rackPipeline: [],
+  totalFlops: 0,
+  totalUptime: 1,
+  totalRackCount: 0,
+};
+
+// --- Locations (unchanged) ---
 
 export type LocationId = 'us-west' | 'us-east' | 'eu-west' | 'eu-north' | 'asia-east' | 'asia-south' | 'middle-east';
 
@@ -41,24 +120,6 @@ export interface LocationConfig {
   availableAt: Era;
 }
 
-export interface GpuConfig {
-  type: GpuType;
-  name: string;
-  flopsPerUnit: number;
-  basePowerDraw: number;
-  basePrice: number;
-  availableAt: Era;
-}
-
-export const GPU_CONFIGS: Record<GpuType, GpuConfig> = {
-  consumer: { type: 'consumer', name: 'Consumer GPU', flopsPerUnit: 1, basePowerDraw: 0.3, basePrice: 800, availableAt: 'startup' },
-  t4: { type: 't4', name: 'NVIDIA T4', flopsPerUnit: 8, basePowerDraw: 0.5, basePrice: 5_000, availableAt: 'startup' },
-  a100: { type: 'a100', name: 'NVIDIA A100', flopsPerUnit: 40, basePowerDraw: 1.0, basePrice: 15_000, availableAt: 'scaleup' },
-  h100: { type: 'h100', name: 'NVIDIA H100', flopsPerUnit: 120, basePowerDraw: 1.2, basePrice: 35_000, availableAt: 'scaleup' },
-  b200: { type: 'b200', name: 'NVIDIA B200', flopsPerUnit: 400, basePowerDraw: 1.5, basePrice: 50_000, availableAt: 'bigtech' },
-  custom: { type: 'custom', name: 'Custom ASIC', flopsPerUnit: 800, basePowerDraw: 1.0, basePrice: 80_000, availableAt: 'agi' },
-};
-
 export const LOCATION_CONFIGS: Record<LocationId, LocationConfig> = {
   'us-west': { id: 'us-west', name: 'US West (Oregon)', energyCostMultiplier: 1.0, latencyTier: 1, regulatoryStrictness: 0.3, politicalStability: 0.9, availableAt: 'startup' },
   'us-east': { id: 'us-east', name: 'US East (Virginia)', energyCostMultiplier: 1.1, latencyTier: 1, regulatoryStrictness: 0.3, politicalStability: 0.9, availableAt: 'startup' },
@@ -68,17 +129,3 @@ export const LOCATION_CONFIGS: Record<LocationId, LocationConfig> = {
   'asia-south': { id: 'asia-south', name: 'Asia South (Mumbai)', energyCostMultiplier: 0.6, latencyTier: 3, regulatoryStrictness: 0.2, politicalStability: 0.7, availableAt: 'bigtech' },
   'middle-east': { id: 'middle-east', name: 'Middle East (UAE)', energyCostMultiplier: 0.5, latencyTier: 3, regulatoryStrictness: 0.1, politicalStability: 0.6, availableAt: 'bigtech' },
 };
-
-export const INITIAL_INFRASTRUCTURE: InfrastructureState = {
-  dataCenters: [],
-  gpuMarketPrices: {
-    consumer: 800,
-    t4: 5_000,
-    a100: 15_000,
-    h100: 35_000,
-    b200: 50_000,
-    custom: 80_000,
-  },
-  totalFlops: 0,
-  totalUptime: 1,
-};

packages/shared/src/types/research.ts

@@ -31,9 +31,9 @@ export interface ResearchNode {
 }
 
 export interface ResearchEffect {
-  type: 'unlock_gpu' | 'unlock_model_tier' | 'efficiency_boost'
+  type: 'unlock_gpu' | 'unlock_rack' | 'unlock_dc_tier' | 'unlock_model_tier'
-    | 'capability_boost' | 'cost_reduction' | 'unlock_feature'
+    | 'efficiency_boost' | 'capability_boost' | 'cost_reduction'
-    | 'unlock_product_line' | 'safety_boost';
+    | 'unlock_feature' | 'unlock_product_line' | 'safety_boost';
   target: string;
   value: number;
 }