What strategies can be used to ensure the scalability of a REST API?

Short answer: Horizontal scaling → Add more servers/containers. Load balancing across multiple instances. Database optimization (indexes, partitioning, read replicas). Caching at server, client, and CDN levels. Use asynchronous processing for long-running tasks. Apply rate limiting and throttling to prevent abuse. Adopt microservices architecture for modular scaling.

Real-world example (ShopNest)

Creating an order is POST /api/orders → 201 with Location header. Fetching is GET /api/orders/{id} → 200 or 404.

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.