• Reliability

  Failover

  Failover is the automatic switch of live traffic from a failing primary system to a healthy standby so users keep being served during an outage. It relies on continuous health checks, a routing layer that can redirect quickly, and a standby kept warm enough to absorb the diverted load.

• Release management

  Feature flag

  A feature flag is a runtime switch in code that turns a piece of functionality on or off without redeploying. Teams use flags to ship code dark, expose features to a subset of users, run A/B tests, and instantly disable broken features - decoupling deployment from release and shrinking the blast radius of a bad change.

• Testing

  Flaky test

  A flaky test passes and fails on the same code without any change, because the outcome depends on timing, environment, or shared state rather than the code under test. Flakies erode trust in CI, hide real regressions behind noise, and slow every pipeline that has to rerun them, so fixing or quarantining them is a first-order engineering task.