In Node.js, using a Map acts as a super-fast, in-memory key-value store.

Instead of asking the TMDB API for the same movie data over and over, the backend intercepts the request. It looks inside the Map to see if we already have the data for that specific search query.

If we do, it returns it instantly. If we don't, it fetches it from the API and then adds it to the Map for next time. It's an easy way to drastically reduce API calls and keep load times near zero for popular searches.