Same thought! Python uses FastAPI. C# with ASP.NET looks similarly terse, and ASP.NET is “built in” (kinda).

var app = WebApplication.Create();

app.MapGet("/people", () => new[] { new Person("Ana"), new Person("Filipe"), new Person("Emillia") });

app.Run();

record Person(string Name);

The above (struggling to find the backtick on my Mobile keyboard) is straight from the ASP.NET website: https://dotnet.microsoft.com/en-us/apps/aspnet/apis