Why modern .NET libraries are migrating from Reflection to Roslyn Source Generators:

Reflection inspects types dynamically at runtime via metadata tables, which incurs execution latency, boxing, and prevents trimming in NativeAOT.

How Incremental Source Generators Work:

1. Implement IIncrementalGenerator.
2. Filter syntax nodes via context.SyntaxProvider.CreateSyntaxProvider().
3. Emit pure C# source files directly into the compilation pipeline (context.RegisterSourceOutput()).

The generated code compiles as native C# code with 0 runtime reflection overhead and 100% NativeAOT compatibility!

System.Text.Json source generator ([JsonSerializable]) is a prime example: serialization throughput jumped by 40% while slashing startup times.

Incremental generators are cache-friendly: they only re-run when the specific annotated source files change, keeping IDE typing responsive.