Configuration Core Principles 1. Options pattern always — Never read directly in services. Bind configuration sections to strongly-typed classes with validation. 2. Validate on startup — Use and to catch misconfiguration before the first request. 3. Secrets never in source — Use user secrets in development, Azure Key Vault or environment variables in production. Never commit secrets to git. 4. Configuration layering — → → environment variables → user secrets. Later sources override earlier ones. Patterns Options Pattern Injecting Options Custom Validation (Complex Rules) Azure Key Vault (Prod…