ASP.NET Core

Web APIs and apps on .NET.

ASP.NET Core is taught here in 14 lessons, running from Minimal APIs through to Real-time features with SignalR. Each lesson takes one topic, shows the working code, and links onward to the next, so the course can be read straight through in order.

Lessons

1. Minimal APIsBuild an HTTP API with route handlers, typed results and endpoint groups, and know when the minimal model is enough.
2. Controllers, dependency injection and middlewareController-based APIs, the three service lifetimes and the middleware order that decides whether authentication runs before routing.
3. Configuration and loggingHow the configuration stack layers sources, the options pattern for typed settings, and structured logging that is worth reading at 3am.
4. Routing and model bindingRoute templates decide which endpoint runs, and the binding rules decide what it receives. Most "parameter is always null" bugs live in the second part.
5. Model validation and Problem Details responsesData annotations, automatic 400 responses and a consistent error shape that a client can parse without guessing.
6. Authentication and authorisationSchemes, policies and requirements, plus the difference between a user being logged in and a user being allowed to touch this row.
7. Data access with Entity Framework CoreDbContext lifetime, migrations, loading strategies and the N+1 queries that turn a fast endpoint into a slow one.
8. Razor Pages and MVC viewsPage models group a URL's handlers with its markup, and tag helpers remove the stringly-typed parts of a view.
9. Static files, uploads and streaming responsesServing assets with the right cache headers, accepting uploads without buffering them into memory, and streaming large responses.
10. CORS, JSON options and API conventionsCORS configured once and safely, JSON options set in one place, and output caching that respects the Vary header.
11. Error handling, health checks and resilienceOne exception handler, health endpoints that mean something, and outbound calls with timeouts, retries and a circuit breaker.
12. Testing ASP.NET Core applicationsWebApplicationFactory runs the real pipeline in memory, which catches the wiring bugs a unit test cannot see.
13. Interactive UI with BlazorServer, WebAssembly and hybrid differ in where the code runs. That single decision drives latency, deployment and what a component can do.
14. Real-time features with SignalRHubs, groups and reconnection, and the scaling decision that has to be made before the first user connects, not after.

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