What is database sharding, and when should you implement it in a microservices architecture?

Short answer: cross multiple machines or instances. When to implement: When you need to scale horizontally: When your database grows beyond the capabilities of a single machine or instance, sharding helps distribute the load.

Real-world example (ShopNest)

ShopNest splits Catalog, Cart, Order, and Payment into services so teams can deploy catalog changes without redeploying payments.

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.