Know what to improve before the real interview.

1type CacheEntry<T> = {
2  expiresAt: number;
3  value: Promise<T>;
4};
5
6const cache = new Map<string, CacheEntry<unknown>>();
7
8export async function cachedFetch<T>(
9  key: string,
10  load: () => Promise<T>,
11  ttlMs = 30_000,
12): Promise<T> {
13  const now = Date.now();
14  const hit = cache.get(key) as CacheEntry<T> | undefined;
15
16  if (hit && hit.expiresAt > now) return hit.value;
17
18  const value = load().catch((error) => {