diff --git a/src/shared/game/entities/Settlement.ts b/src/shared/game/entities/Settlement.ts
index 5a1aa1c..986032f 100644
--- a/src/shared/game/entities/Settlement.ts
+++ b/src/shared/game/entities/Settlement.ts
@@ -65,13 +65,19 @@ export function createSettlement(
  * - Available units (RURE occupation) do not count.
  */
 export function calculatePopulation(settlement: Settlement): number {
-  return settlement.units.filter((u) => {
-    const occ = u.occupation;
+  // ⚡ Bolt: Use a simple loop with a counter instead of filter().length to avoid intermediate array allocation.
+  let count = 0;
+  for (const unit of settlement.units) {
+    const occ = unit.occupation;
     // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
-    if (!occ) return false;
+    if (!occ) continue;
     // JobType is a string
-    if (typeof occ === 'string') return true;
-    // FieldWork and Rure are objects
-    return occ.kind === 'FIELD_WORK';
-  }).length;
+    if (typeof occ === 'string') {
+      count++;
+    } else if (occ.kind === 'FIELD_WORK') {
+      // FieldWork is an object
+      count++;
+    }
+  }
+  return count;
 }
diff --git a/src/shared/game/systems/TurnEngine.ts b/src/shared/game/systems/TurnEngine.ts
index ddd64e8..29103df 100644
--- a/src/shared/game/systems/TurnEngine.ts
+++ b/src/shared/game/systems/TurnEngine.ts
@@ -16,6 +16,9 @@ export interface TurnEngineResult {
   readonly effects: readonly GameEffect[];
 }
 
+const BUILDING_TYPES_SET = new Set<string>(Object.values(BuildingType));
+const UNIT_TYPES_SET = new Set<string>(Object.values(UnitType));
+
 /* eslint-disable-next-line @typescript-eslint/no-extraneous-class */
 export class TurnEngine {
   private constructor() {
@@ -155,8 +158,9 @@ export class TurnEngine {
       return currentNamingStats;
     }
 
-    const isBuilding = Object.values(BuildingType).includes(currentItem as BuildingType);
-    const isUnit = Object.values(UnitType).includes(currentItem as UnitType);
+    // ⚡ Bolt: Use pre-calculated Sets for O(1) lookup instead of creating new arrays with Object.values()
+    const isBuilding = BUILDING_TYPES_SET.has(currentItem);
+    const isUnit = UNIT_TYPES_SET.has(currentItem);
     const cost = this.getProductionCost(currentItem, isBuilding);
 
     if (!this.canAffordConstruction(settlement, cost)) {