Manage application configuration including environment variables, settings management, configuration hierarchies, secret management, feature flags, and 12-factor app principles. Use for config, environment setup, or settings management.

Configuration Management Table of Contents [Overview]( overview) [When to Use]( when to use) [Quick Start]( quick start) [Reference Guides]( reference guides) [Best Practices]( best practices) Overview Comprehensive guide to managing application configuration across environments, including environment variables, configuration files, secrets, feature flags, and following 12 factor app methodology. When to Use Setting up configuration for different environments Managing secrets and credentials Implementing feature flags Creating configuration hierarchies Following 12 factor app principles Migrating configuration to cloud services Implementing dynamic configuration Managing multi tenant configurations Quick Start Minimal working example: Reference Guides Detailed implementations in the references/ directory: Guide Contents [Environment Variables](references/environment variables.md) Environment Variables [Configuration Hierarchies](references/configuration hierarchies.md) Configuration Hierarchies [Secret Management](references/secret management.md) Secret Management [Feature Flags](references/feature flags.md) Feature Flags [12 Factor App Configuration](references/12 factor app configuration.md) 12 Factor App Configuration [Configuration Validation](references/configuration validation.md) Configuration Validation [Dynamic Configuration (Remote Config)](references/dynamic configuration remote config.md) Dynamic Configuration (Remote Config) Best Practices ✅ DO Store configuration in environment variables Use different config files per environment Validate configuration on startup Use secret managers for sensitive data Never commit secrets to version control Provide sensible defaults Document all configuration options Use type safe configuration objects Implement configuration hierarchy (base + overrides) Use feature flags for gradual rollouts Follow 12 factor app principles Implement graceful degradation for missing config Cache secrets to reduce API calls ❌ DON'T Hardcode configuration in source code Commit .env files with real secrets Use different config formats across services Store secrets in plain text Expose configuration through APIs Use production credentials in development Ignore configuration validation errors Access process.env directly everywhere Store configuration in databases (circular dependency) Mix configuration with business logic

configuration-management