Session Persistence in Load Balancers: Set session persistence or affinity policies?

Short answer: in the load balancer (e.g., AWS ELB or Azure Load Balancer) to ensure that subsequent requests from the same user are directed to the same microservice instance.

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.