Everything you can’t do with environment variables (and what you actually should)

Environment variables are essential for process-level configuration across various platforms, providing a universal interface for settings like database connection strings, API keys, and service URLs. However, their limitations become evident when used for runtime decisions, such as per-request context, gradual rollouts, and operational urgency, as they are static and require process restarts for changes. The article argues that while environment variables are effective for stable, context-free values that don't require frequent changes, they fall short for more dynamic needs, leading teams to inadvertently build feature flag systems to compensate. It suggests that environment variables should be used appropriately within their intended scope, and for more complex requirements, runtime controls with features like feature flags and contextual evaluation should be employed. This discussion is part of a broader series on FeatureOps, exploring the challenges of stretching static configuration tools beyond their designed capabilities.