Reliability

Circuit Breaker

After N consecutive failures, stop calling a dependency for a cooldown, then probe with a half-open state.

Why interviewers ask about it

Gives a struggling dependency room to recover instead of holding it underwater with continued traffic.

Capping retries as a fraction of total traffic rather than as a fixed count per request.

Bounded, separate resource pools per dependency so one slow dependency cannot starve the others.

This term is part of the free System Design interview preparation module - browse the full glossary for every definition.