Feature Flags

In this first step of exposure strategies, we will investigate feature flags. A feature flag is a conditional in your code, an if, then for two different options. At its simplest, a feature flag can be used to flag new or risky behaviour. First, the feature is deployed off. Then, separate from deployment, you can turn on the new feature.

If the feature doesn’t behave as expected, it is possible to shut it off quickly. This is better than rolling back an entire version because you have isolated the change. In addition, it allows development on other features to continue without forcing a complete rollback. In effect, you’re isolating the change while your codebase evolves around it. Risk is the uncertainty of unknown issues. With feature flagging, you’re mitigating risk by making every feature encapsulated and controlled.

Feature flags are effective for risk mitigation, fast feedback, hypothesis-driven development, and long-term control. There’s no one right way to use feature flags.

In the following step, we will learn about experimentation.