What are Hosted Services in ASP.NET Core?

Hosted Services in ASP.NET Core provide a standard mechanism for running background tasks within the application's hosting environment. They are useful when work needs to happen independently of an incoming HTTP request. Common examples include: Processing messages from a queue Scheduled background operations Data synchronization Sending notifications Periodic cleanup Processing long-running tasks Polling external systems ASP.NET Core provides the IHostedService interface, while BackgroundService provides a convenient base class for implementing long-running background workers. A simplified example is: public class OrderProcessingService : BackgroundService { protected override async Task ExecuteAsync( CancellationToken stoppingToken) { while (!stoppingToken.IsCancellationRequested) { await ProcessOrdersAsync(stoppingToken); await Task.Delay(TimeSpan.FromMinutes(1), stoppingToken); } } } Enterprise considerations Background services need careful handling of: Cancellation Graceful shutdown Exceptions Retry policies Concurrency Dependency scopes Logging Monitoring Duplicate processing Long-running operations For example, if a worker processes messages from a queue and crashes after performing an operation but before acknowledging the message, the same message may potentially be processed again. Applications therefore need appropriate idempotency and retry strategies. Hosted Services are excellent for many background workloads, but they are not automatically the best choice for every workload. For highly critical, independently scalable, or long-running processing, a dedicated worker architecture or managed messaging/serverless service may be more appropriate. The key idea is that Hosted Services allow ASP.NET Core applications to perform background work without tying that work directly to HTTP requests.