Feature flag rollouts that stick

Feature flags are great until they are not. A sloppy rollout can hide broken behavior or leave cruft in your codebase for months. This is the checklist we lean on to keep flags disciplined and short-lived.

Create the flag with an expiry plan

• Define the owner, removal date, and cleanup steps in the flag description.
• Add a tracking card in the delivery board with a reminder two weeks before expiry.
• Prefer boolean flags for risky toggles and multivariate flags for gradual exposure.

Ship with guardrails

1. Roll out to internal users first, validating metrics and logs while error budgets stay healthy.
2. Expand to 5–10% of traffic using automated canary analysis where possible.
3. Bake for at least one peak traffic window before going broader.

Observe, then remove

We watch three signals during the rollout: error rate deltas, latency percentiles, and key business conversions. Once the flag hits 100% for a full day without regression, we schedule the removal PR immediately.

Keeping a tight loop around flags reduces surprise outages and keeps the codebase lean.