// Feature Flags - The Art of the IF and Deployment

Feature flags (also called feature toggles) are one of the most powerful — and most misunderstood — practices in modern software delivery. This session explores them from first principles through to production implementation.

What are feature flags?

A mechanism to decouple deployment (pushing code to production) from release (enabling that code for users). Once separated, teams can deploy continuously, roll out incrementally, experiment in production, and roll back instantly — without touching infrastructure.

Types of feature flags covered

• Release flags — control when a new feature becomes visible to users
• Experiment flags — A/B testing and gradual rollout
• Ops flags — circuit breakers and kill switches for production incidents
• Permission flags — per-user or per-cohort feature access

Best practices discussed

• Wrap all significant code changes in flags from the start — retrofitting is painful
• Use additive database changes: add new columns alongside existing ones so old and new code can coexist safely in production; deprecate and remove only after full rollout
• Establish clear flag lifecycle policies — flags that are never cleaned up become long-term debt

Tooling walk-through

• Azure App Configuration — integrates natively with ASP.NET Core’s configuration system; feature management libraries support Razor views, controller actions, and middleware with dynamic reload
• LaunchDarkly — injects into the same .NET configuration pipeline; SDKs cover Java, Python, Node, JavaScript, and mobile platforms
• Optimizely — experimentation-focused with broad SDK and platform support

Prerequisites

CI/CD pipelines, automated quality gates, and trunk-based development are non-negotiable foundations. Feature flags without these in place become a liability rather than an asset — and the nervous feeling before a big production release is often the signal that it’s time to start.

Chris closes with an interesting observation: even a Hugo-based static site served via Azure Static Web Apps can benefit from feature flags — “static” refers to the files, not the user experience.