7 articles tagged with "microservices"
Code coverage tells you which lines ran. It says nothing about whether your assertions would notice if the logic on those lines were wrong. Mutation testing fixes that by breaking your code on purpose — here's how it works and why your 'green' suite might be a green screen of nothing.
You configured sampling on every service. Each one is working exactly as designed. And yet your traces keep showing up with chunks missing, like a comic book where someone tore out every third page. Here's why, and how consistent sampling fixes it.
Your monolith had ROLLBACK. Your microservices don't. The saga pattern is how you fake a distributed transaction using nothing but events, compensating actions, and the quiet acceptance that everything is eventually consistent.
Everyone name-drops the circuit breaker pattern in system design interviews. Far fewer have actually tuned one that survives contact with production. Here's what the tutorials skip: half-open state thrash, per-dependency breakers, and why a breaker with no fallback is just a fancier 500.
The classic test pyramid assumes one codebase, one deploy, one team. Split that into fifteen services and the shape quietly stops making sense. Here's what actually works when 'integration' means 'a network call to someone else's team.'
Your unit tests pass, your integration tests pass, and then production breaks because Service A renamed a field that Service B depended on. Contract testing is the missing layer that catches this before it ships.
Distributed transactions are where microservices go to cry. The saga pattern gives you eventual consistency without locking every service in a two-phase commit death grip — here's how it actually works.