Real-world Use Cases?

🏦 Fintech API – Global Exception Filter

Ensures consistent error envelopes across microservices.

🛠 Microservices – Audit Logging

Tracks when sensitive controller actions are executed.

👮 Role-based Authorization

Custom authorization filter validating role claims dynamically.

🚀 Performance Profiling

Times how long each controller method takes.

public class ProfilingFilter : IActionFilter
{
private Stopwatch _watch;
public void OnActionExecuting(ActionExecutingContext context)
{
_watch = Stopwatch.StartNew();
}
public void OnActionExecuted(ActionExecutedContext context)
{

_watch.Stop();

Console.WriteLine($"Action took {_watch.ElapsedMilliseconds}

ms");

}
}