Should I use feature flags in CI/CD or only in production?

Use feature flags in both CI/CD and production, but for different purposes.

In CI/CD

Feature flags are useful to:

• Test unfinished code safely without merging it behind long-lived branches
• Run dark launches and verify behavior in staging or pre-prod
• A/B test or validate migrations before full release
• Enable/disable flaky or risky features during automated pipelines

This helps keep your deployment pipeline moving while reducing merge risk.

In production

Feature flags are especially valuable to:

• Roll out gradually to a small percentage of users
• Kill switch problematic features quickly without redeploying
• Target specific users/segments for beta releases
• Decouple deploy from release so code can ship before exposure

Best practice

Use them as a lifecycle tool:

• Develop/CI: keep incomplete work off by default
• Staging/UAT: enable to validate behavior
• Production: control exposure and rollback safely
• Cleanup: remove flags once they’re no longer needed

Watch out

Avoid letting flags become permanent:

• Too many flags increase complexity
• Old flags can create confusing code paths
• Always have an owner and expiration date

If you want, I can also give you a recommended feature-flag strategy by environment (dev, CI, staging, prod).