Secret management (e.g. user secrets, Azure Key Vault)?

Short answer: User Secrets (for local dev): dotnet user-secrets init dotnet user-secrets set "MySettings:ApiKey" "secret" Azure Key Vault: builder.Configuration.AddAzureKeyVault(...); ✅ Secure sensitive data like API keys, connection strings, tokens.

Real-world example (ShopNest)

A ShopNest checkout request flows through middleware, hits a minimal API or controller, uses scoped services, and returns ProblemDetails on errors.

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.