Development
How do you implement feature flags in production?
Feature flags wrap new functionality in conditional checks that can be toggled without deploying new code. Implement them using a feature flag service (LaunchDarkly, Unleash, Flagsmith) or a simple config-driven approach with a database-backed toggle. The flag evaluation runs server-side on each request, enabling gradual rollouts, A/B tests, and instant kill switches.
Key Considerations
- Start with a boolean flag per feature; add percentage rollouts and user targeting as you mature
- Always define a flag lifecycle — remove flags within 30–90 days of full rollout to prevent tech debt
- Server-side evaluation is more secure than client-side for anything access-controlled
- Use feature flags for decoupling deployment from release — deploy dark code daily, release when ready
- Self-hosted options (Unleash, Flagsmith) avoid vendor lock-in and per-seat pricing that scales poorly