▸case-01 I am building a React 18 user interface for an enterprise portal that connects to a .NET backend. How should I manage global client-side UI state and component re-renders across nested frontend views? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-16 In an ASP.NET Core `Program.cs`, a developer placed `app.UseAuthorization();` before `app.UseRouting();`. Requests fail or authorization attributes are ignored. What is the correct order of HTTP middleware? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-17 An ASP.NET Core controller returns raw Entity Framework Core `User` entities directly from `[HttpGet] public ActionResult<User> GetUser(int id)`. This exposes password hashes and causes circular serialization errors. How should backend layering fix this? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-09 In a .NET 8 Web API, a developer registered `DbContext` as a Singleton service using `builder.Services.AddSingleton<MyDbContext>()`. What severe bugs will this cause and what is the correct registration? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-08 We need to cache user session profiles in an ASP.NET Core Web API to reduce DB load. A developer suggested storing them in a static C# `ConcurrentDictionary` in API memory. What is the production-grade approach for scalable caching? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-15 A high-throughput C# microservice uses Dapper for SQL queries. A developer wrote: `connection.Query<User>("SELECT * FROM Users WHERE Email = '" + email + "'");`. What critical flaw exists and how should Dapper queries be executed? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-10 We are building an MCP (Model Context Protocol) server in C# .NET to expose backend tools to an AI assistant. How should tool registration, invocation schemas, and JSON-RPC transport protocol handlers be structured in .NET? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-11 A developer is writing logs in a C# service like this: `_logger.LogInformation($"User {userId} placed order {orderId} for amount {amount}");`. What is bad about string interpolation here, and how should it be fixed? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-13 Our Kubernetes cluster needs to check if our .NET backend API and its downstream PostgreSQL and Redis databases are ready to serve traffic. How should health check monitoring be configured in ASP.NET Core? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-02 We need to fix layout overflow issues in our client application using Tailwind CSS classes for flexbox containers. How should we structure the CSS grid and flex utility classes in the React frontend markup? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-14 We want to write automated integration tests for our ASP.NET Core REST API that send real HTTP requests through the full pipeline without hosting on a live port. How should the test harness be set up in C#? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-07 Our C# backend calls a flaky third-party REST API over HTTP. Currently, network glitches or transient HTTP 503 responses cause immediate uncaught exceptions in our API. How should transient fault resilience be implemented in .NET 8? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-22 Our ASP.NET Core `Program.cs` file has grown to over 3,000 lines because every Minimal API `app.MapGet` and `app.MapPost` lambda is defined directly in `Program.cs`. How should Minimal API endpoints be modularized? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-06 An ASP.NET Core API endpoint fetches a list of Customer entities, loops through each customer with `foreach`, and accesses `customer.Orders.Count` causing hundreds of SQL queries. How should this EF Core query be optimized? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-04 In an ASP.NET Core 8 API, developers are directly injecting `IConfiguration` into dozens of domain services and calling `_config["PaymentGateway:TimeoutSeconds"]` directly. We want to clean this up. How should configuration be bound and injected into backend services? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-21 In our domain layer, monetary amounts are represented as raw `decimal` primitive properties on entities without currency checks, leading to invalid math operations like adding USD to EUR. How should C# backend patterns encapsulate domain invariants? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-12 When an unhandled exception occurs in our ASP.NET Core Web API, the controller catches `Exception ex` and returns `Ok(new { success = false, error = ex.Message })`. How should standardized error handling be implemented? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-20 When a user cancels an HTTP request in our ASP.NET Core API, the server continues running long 30-second database queries and downstream HTTP calls to completion. How should cancellation be propagated? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-05 A C# backend developer wrote the following endpoint method to fetch orders: `var orders = _context.Orders.Where(o => o.IsActive).ToList();` or calls `.Result` on async methods in Web API controllers. What is wrong with this approach and how should it be rewritten for production? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-03 We are developing a Python FastAPI backend service with SQLAlchemy ORM. How should we structure the dependency injection system and async database session management in FastAPI? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-18 Under heavy concurrent traffic, when a key expires in Redis, 500 API threads simultaneously run the expensive SQL query to recalculate the cached value, crashing the database. How should cache stampede / thundering herd be mitigated in .NET? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-19 We created a C# `BackgroundService` class to process queued orders every minute. The developer injected `MyDbContext` directly into the `BackgroundService` constructor, causing `ObjectDisposedException` or cross-thread errors. How should scoped dependencies be resolved in background tasks? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |