By preventing calls to failing services. Frame the concept in practical terms so you can explain it during interview discussion.
Resilience4j is a Java library that helps implement circuit breakers, which stop calls to a service when it is failing, preventing resource exhaustion. For example, if a payment service is down, the circuit breaker can open, halting further requests until the service is stable again.
Additional Notes
How does Resilience4j apply circuit breakers in Java?