With every service/third-party API's implementation in a system, it adds up an uncertainty around it. Circuit Breaker pattern helps in building resilient systems, handling error gracefully and prevents applications from failing through cascading.
As per Martin Fowler: The basic idea behind the circuit breaker is very simple. You wrap a protected function call in a circuit breaker object, which monitors for failures. Once the failures reach a certain threshold, the circuit breaker trips, and all further calls to the circuit breaker return with an error, without the protected call being made at all.
Check out dev.to post. It has Examples codes with success and failure scenarios written in Javascript.
https://dev.to/boxpiperapp/circuit-breaker-pattern-build-bet...
Good Read.