CI/CD & Dev Process · Level 2
Shipping safely
Mission briefing
Mission 4-B: A half-finished feature — one you're still designing — just appeared on the live site. Real users can see it. It's not ready. The question in the channel is calm but pointed: "how is this live?"
Unfinished work should sit behind a feature flag — a switch that hides a feature from users until you flip it on. The code can ship to production while the feature stays invisible. Someone flipped this one early, or it never got wrapped in a flag at all.
When code goes to production, that's a deploy — the act of releasing a version to a live environment. The feature got deployed with the flag accidentally on. The deploy itself worked fine; the visibility switch was the problem.
Quickest fix: flip the flag off. If that weren't possible, we'd rollback — return to the previous known-good version, like an undo for the whole site. And the flag's default state is set by an environment variable, a setting that lives outside the code and differs per environment.
Flag off. The feature vanishes from production, still safe and intact in our work. No rollback needed. I'm realizing feature flags are a design tool too — they're how you'd run a gradual rollout.
A not-yet-ready feature is visible in production. Fastest safe fix?