AI scaffolded NodeJS version of the App.

app-new/backend/src/cache.ts

@@ -0,0 +1,29 @@
+type CacheEntry<T> = {
+  value: T;
+  expiresAt: number;
+};
+
+export class MemoryCache {
+  private readonly store = new Map<string, CacheEntry<unknown>>();
+
+  public get<T>(key: string): T | undefined {
+    const hit = this.store.get(key);
+    if (!hit) {
+      return undefined;
+    }
+
+    if (Date.now() >= hit.expiresAt) {
+      this.store.delete(key);
+      return undefined;
+    }
+
+    return hit.value as T;
+  }
+
+  public set<T>(key: string, value: T, ttlMs: number): void {
+    this.store.set(key, {
+      value,
+      expiresAt: Date.now() + ttlMs
+    });
+  }
+}