Blog

Mert Özen's blog posts on software development, backend, frontend, and DevOps.

Series

What's New in .NET 10: AddValidation, OpenAPI 3.1 and Server-Sent Events in ASP.NET Core

.NET 10 LTS brings AddValidation to minimal APIs, OpenAPI 3.1 and YAML, TypedResults.ServerSentEvents, System.Text.Json-based JSON Patch, dotnet run app.cs, C# 14 and breaking changes such as cookie auth 401/403.

4 Nov 2026 9 min 2

Backend PART 35

What's New in .NET 9: Built-in OpenAPI, Scalar and HybridCache in ASP.NET Core

.NET 9 drops Swashbuckle from the template: AddOpenApi/MapOpenApi, transformers, Scalar and Swagger UI, stampede-safe HybridCache, TypedResults.InternalServerError, StatusCodeSelector, C# 13 and 24-month STS support.

4 Nov 2026 9 min 2

Backend PART 26

Swagger and OpenAPI in ASP.NET Core Web API: Documentation with Swashbuckle

We add an OpenAPI document and Swagger UI to an ASP.NET Core Web API with Swashbuckle: the right package version, XML comments, documenting response types, an Authorize button for JWT, and common pitfalls with real error messages.

4 Nov 2026 10 min 2