Inter-Service Communication: Microservices often interact with each other through?

Short answer: APIs. Contract testing ensures that the contract (e.g., API request/response format) is adhered to on both sides.

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.