Kestrel behind IIS
Explain how ASP.NET Core is hosted on IIS compared to classic ASP.NET Framework apps.
Answers use simple, clear English.
Quick interview answer
Classic ASP.NET runs inside IIS on System.Web. ASP.NET Core uses Kestrel; on Windows, IIS often reverse-proxies via ASP.NET Core Module (in-process or out-of-process). IIS can still do TLS, Windows auth, and request filtering.
Detailed answer
Classic ASP.NET runs inside IIS on System.Web. ASP.NET Core uses Kestrel; on Windows, IIS often reverse-proxies via ASP.NET Core Module (in-process or out-of-process). IIS can still do TLS, Windows auth, and request filtering. Linux typically uses Nginx/Caddy → Kestrel. Framework apps don't use Kestrel.
Real example & use case
web.config hostingModel=OutOfProcess; ANCM forwards to dotnet MyApp.dll.
Pros & cons
Pros: modern runtime with familiar IIS edge. Cons: ANCM misconfig → 502.5 errors.