Fail Fast
ELI5 — The Vibe Check
Fail fast means if something is going to go wrong, it should go wrong immediately — not five minutes and three API calls later. Validate inputs at the door. Check permissions before doing work. Throw errors early and loudly. The alternative is failing slowly and silently, which is like a car with no dashboard warning lights — everything seems fine until the engine falls out.
Real Talk
Fail fast is a design philosophy where systems detect and report errors as close to the source as possible. It encompasses input validation at system boundaries, precondition checks, assertion-based programming, and circuit breakers. Fail-fast systems are easier to debug because errors occur near their cause rather than manifesting as mysterious downstream failures.
When You'll Hear This
"Validate the input first — fail fast if it's invalid." / "The fail-fast approach caught the config error at startup instead of in production traffic."
Related Terms
Circuit Breaker
Circuit Breaker is like the electrical circuit breaker in your house.
Early Return
Early return is exiting a function as soon as you have the answer, instead of setting a variable and waiting until the end.
Error Handling
Error handling is the art of planning for things to go wrong and dealing with them gracefully instead of letting everything catch fire.
Guard Clause
A guard clause is an early return at the top of a function that handles edge cases immediately — like a bouncer at a club. 'No ID? You're out. Under 21?
Input Validation
Input validation is checking that user input is what you expect before using it.