Authorization/authentication in APIs (JWT, OAuth)?

Short answer: Use JWT Bearer Tokens for stateless auth: services.AddAuthentication(JwtBearerDefaults.AuthenticationSch eme) .AddJwtBearer(options => { ... }); Secure endpoints with: [Authorize(Roles = "Admin")] OAuth supported via IdentityServer, Azure AD, or external providers.

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.