How to organize the execution of code to run only after the request processing is completed?

In C#, to execute code after the request processing is completed, asynchronous methods and await are usually used to wait for the operation to finish.

If it's a web application, such as ASP.NET, middleware or events that trigger after request processing can be used.

Example with an asynchronous method:

public async Task<IActionResult> HandleRequest()
{
    // Request processing
    await ProcessRequestAsync();

    // Code that runs after processing is complete
    PostProcess();

    return Ok();
}

If you need to execute code exactly after the full completion of the request at the server level, you can use middleware:

public class AfterRequestMiddleware
{
    private readonly RequestDelegate _next;

    public AfterRequestMiddleware(RequestDelegate next)
    {
        _next = next;
    }

    public async Task InvokeAsync(HttpContext context)
    {
        await _next(context); // Request processing

        // Code that runs after request processing
        AfterRequestLogic();
    }
}

Thus, the code runs after the request processing is finished.