DTOs and mapping (e.g. AutoMapper)?

Short answer: DTOs decouple internal models from API contracts. Use AutoMapper for mapping: CreateMap<Product, ProductDto>(); var dto = _mapper.Map<ProductDto>(product);

Example code

DTOs decouple internal models from API contracts. Use AutoMapper for mapping: CreateMap<Product, ProductDto>(); var dto = _mapper.Map<ProductDto>(product);

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.