ASP.NET Core Interview Question #175

What are best practices for logging, error handling, and background services in ASP.NET Core?

Logging, Error Handling & Background Services Mid-Level Intermediate

Quick Interview Answer

Use structured ILogger messages with meaningful properties and appropriate log levels. Centralize unhandled exception processing, return safe and consistent production errors, and preserve detailed diagnostics in protected logs rather than exposing them to users.

Detailed Explanation

Use structured ILogger messages with meaningful properties and appropriate log levels. Centralize unhandled exception processing, return safe and consistent production errors, and preserve detailed diagnostics in protected logs rather than exposing them to users.

For background services, observe cancellation, create scopes for scoped dependencies, handle only failures that can be meaningfully recovered from, and use deliberate retry/backoff strategies for transient errors. Consider durable queues or schedulers when work must survive process restarts.

Add health checks and production observability so failures can be detected quickly. Correlate logs, metrics, and traces, and never allow diagnostic convenience to expose secrets or sensitive user data.

Code Example

builder.Services.AddProblemDetails();
builder.Services.AddExceptionHandler<GlobalExceptionHandler>();
builder.Services.AddHealthChecks();
builder.Services.AddHostedService<QueueWorker>();

var app = builder.Build();

app.UseExceptionHandler();
app.MapHealthChecks("/health");

app.Run();