The journey of every round

Implement IExceptionHandler (the .NET 8 abstraction) that maps domain exceptions to ProblemDetails with trace_id from Activity.Current.

Implement IRequestPostProcessor<TRequest, TResponse> in MediatR to log every successful response with structured ILogger<T> properties.

Add a fallback resilience pipeline using ResiliencePipeline.AddFallback that swaps to a cached IDistributedCache value on inner failure.

Use Keyed services (Microsoft.Extensions.DependencyInjection 8.0) to register multiple implementations of an interface and resolve by string key.

Implement schema migration on startup using IHostedService that runs DbContext.Database.MigrateAsync before the host accepts traffic.

Build a typed HttpClient with a DelegatingHandler stack that injects IHttpContextAccessor's current trace ID into outgoing headers.

Use IRequestHandler<TRequest, TResponse> with a request that wraps an IAsyncEnumerable<T> stream for paged streaming response.

Implement a JwtBearerOptions handler that validates a custom claim transformation using IClaimsTransformation in DI.

Add health checks using IHealthCheckPublisher with a custom HealthCheckResult that exposes degraded state metrics.

Implement an IObservable<T> stream over Channel<T> with backpressure, completing on CancellationToken cancellation.

Set up a circuit breaker via ResiliencePipelineBuilder with exponential backoff, AddTimeout, AddRetry, and AddCircuitBreaker stacked.

Add a custom IValidatorFactory hook that resolves AbstractValidator<T> from DI and runs ValidationContext<T> with a custom rule set name.

Write a Roslyn ISourceGenerator that emits boilerplate INotifyPropertyChanged for all [Notify] attributed properties.

Implement a token refresh middleware using IMiddleware (not the convention-based one), with RequestDelegate and DelegatingHandler chained.

Use IRequestPreProcessor<TRequest> in MediatR to inject the current ClaimsPrincipal into every request before handler dispatch.

Add IDistributedCache with backplane invalidation on a config change, using IOptionsMonitor<T> reload notifications.

Wire OpenTelemetry tracing: ActivitySource for traces, Meter for metrics, with ILogger<T> structured logs feeding both.

Implement a custom AuthenticationHandler<TOptions> for a header-based API key, including ChallengeAsync and AuthenticateResult.

Write a BackgroundService that uses IServiceScopeFactory to resolve a scoped DbContext per iteration, with retry via ResiliencePipeline.

Add a Channel<T>-based bounded producer-consumer with backpressure, using BoundedChannelFullMode.Wait and a CancellationToken end-to-end.

Write a custom IPipelineBehavior<TRequest, TResponse> for MediatR that captures FluentValidation errors and re-throws as a structured ValidationException.

Implement a graceful shutdown handler using IHostApplicationLifetime, with a 30-second drain window and structured logging at each phase.

The retailer is asking me to wait 4 weeks for a repair on a faulty appliance. Is that reasonable?

I bought clothing that didn't fit and the shop says they don't accept returns. Are my rights limited because it's a fitting issue?