Building resilient systems with Circuit Breakers.

A Circuit Breaker prevents a network or service failure from cascading by blocking requests to a failing service.

Implemented via libraries like gobreaker or sonyflake. If an external API fails repeatedly, the breaker 'trips' (Open state), instantly rejecting calls to prevent system locking. It waits a timeout period (Half-Open), allows a single test request, and resets (Closed state) if successful.