C# is finally getting union types. After a decade of sealed-class workarounds and OneOf packages, C# 15 ships real unions and closed hierarchies in the .NET 11 preview. Here's what they look like, when to reach for each, and the gotchas the announcement posts won't tell you about.

Most legacy .NET applications don't need a rewrite — they need a plan. Here's how to move a real enterprise codebase from .NET Framework to modern .NET without stopping feature work: async-first data access, structured logging, Polly resilience, health checks, and the strangler fig pattern done right.

Uncle Bob described a multi-agent pipeline where human interaction decreases at each stage — Specifier, Coder, Refactorer, Architect — transforming informal requirements into mutation-tested, property-verified code. Here's what each stage does and how to implement it in .NET.

Before/after demo for migrating enterprise .NET apps to modern .NET — async, DI, EF Core Code First, Polly v8, health checks, Serilog, and the Strangler Fig pattern. Companion repo for the article.

A multi-agent pipeline — Specifier, Coder, Refactorer, Architect — that turns informal requirements into mutation-tested, property-verified .NET code. Companion repo for the article.

Two-tier caching with built-in stampede protection and tag invalidation, replacing the IMemoryCache/IDistributedCache split with one API. Companion repo for the article.