Which deployment strategies do you use and when?
Quick Answer
Rolling update (default, gradual replacement, cheap), blue-green (instant switch and rollback, double infra), canary (gradual traffic shift with metric gates, lowest risk), and recreate (down then up, for incompatible versions).
Detailed Answer
Choose by risk and cost: rolling for routine backward-compatible changes; blue-green when you need instant rollback and can afford duplicate environments; canary for high-risk changes where you want to validate on a small % first (Argo Rollouts/Flagger automate it); recreate only when old and new cannot coexist (e.g., breaking schema). Feature flags complement all of them by decoupling deploy from release.
Interview Tip
Tie each strategy to a risk/cost scenario and add feature flags as the cross-cutting technique — that breadth impresses.