Using ActionResult vs IActionResult?

Q: Using ActionResult vs IActionResult?

Short answer: ActionResult : Combines a return value and response code. public ActionResult Get(int id) { ... } IActionResult: More flexible, returns different result types explicitly. Prefer ActionResult for simpler, strongly-typed APIs. 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 Define — one clear sentence (the short answer above). Example — relate it to a project like ShopNest or your real work. Trade-off — when you would not use it.

Question

Using ActionResult<T> vs IActionResult?

Accepted Answer

Short answer: ActionResult: Combines a return value and response code. public ActionResult Get(int id) { ... } IActionResult: More flexible, returns different result types explicitly. Prefer ActionResult for simpler, strongly-typed APIs. 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 Define — one clear sentence (the short answer above). Example — relate it to a project like ShopNest or your real work. Trade-off — when you would not use it.