.NET 10 Web API from Scratch: Vertical Slice Architecture Explained

Vertical Slice Architecture in .NET 10 Web API: build an ASP.NET Core Minimal API from scratch with FluentValidation, Swagger/OpenAPI, MediatR and a clean C# project structure you can start with today. This is Part 1 of the ClinicFlow series, where we build a real, production-style Web API for outpatient clinics (patients, doctors, appointments). Not a to-do app, but the kind of API you'd actually ship. What you'll learn: ✅ Layered architecture vs Vertical Slice Architecture ✅ A clean project structure: Features and Infrastructure ✅ A 25-line Program.cs: services in, pipeline out, endpoints mapped ✅ Minimal API endpoints with route groups and typed results ✅ A complete use case in one folder: command, handler, validator ✅ FluentValidation with a reusable endpoint validation filter ✅ Built-in OpenAPI in .NET 10 with Swagger UI, plus a live demo ✅ How this setup grows into Clean Architecture + Vertical Slices ⏱️ CHAPTERS 0:00 Intro: what we're building 0:26 Layers vs Vertical Slice Architecture 1:07 Project structure: Features & Infrastructure 2:03 Program.cs and registering features 2:48 Minimal API endpoints & the CreatePatient use case 4:03 FluentValidation and the validation filter 5:05 Infrastructure & API docs (OpenAPI in .NET 10) 5:37 Swagger UI live demo (201, 400, 200, 404) 6:26 Start small, grow into Clean Architecture 6:59 Recap and what's next 📺 Part 2 (MediatR in depth): [   • MediatR in .NET 10 Web API : A Complete Guide  ] 💻 Source code: [https://github.com/sajjadms/clinicflow] 🛠️ Tech stack: .NET 10 · ASP.NET Core Minimal APIs · FluentValidation · MediatR 12 · EF Core 10 · Swagger UI · Visual Studio 2026 If this helped, like the video and subscribe so you don't miss the next part. 🌐 Follow Microcare Academy: Instagram →   / microcare_academy   Facebook →   / microcareacademy   Website → https://microcareacademy.in #dotnet #aspnetcore #webapi #verticalslicearchitecture #csharp