Glossary term
What is Circuit breaker? Meaning for developers
In System Design
Stops calling a failing service for a while. Example: Like a home electrical breaker tripping.
Learn it properly · System DesignLesson 42: Circuit Breaker & Bulkhead PatternsTimeouts limit how long you wait per call, but not how often you keep calling a service you already know is dead. How circuit breakers fail fast and test for recovery, how bulkheads stop one dependency exhausting everything, and how to design honest fallbacks.In Practical Design Problems
After many failures, stop calling a dependency for a while and fail fast. Then test now and then to see if it works again.
Learn it properly · Practical Design ProblemsLesson 7: Design an LRU Cache, Idempotent Payments and Other Classic Mini-ProblemsShort worked designs: an LRU cache, idempotency keys, a job queue with retries and backoff, and feature flags.In AI Engineering
After repeated failures, stop calling a dependency for a while and fail fast.
Learn it properly · AI EngineeringLesson 4: Observability and Guardrails for LLM Features in ProductionWhat to log and what never to log, spans, redaction, schema validation, a circuit breaker, a kill switch, prompt versions and an incident playbook.In Observability & SRE
A switch around a dependency that opens after too many failures and fails calls instantly, then lets a trial call through to test recovery.
Learn it properly · Observability & SRELesson 7: Reliability Patterns: Timeouts, Retries, Circuit Breakers and Graceful DegradationFailure modes, timeouts and retries with backoff, circuit breakers, bulkheads, load shedding, tested with fault injection.