A detailed comparison of C# reflection and source generators in .NET 10, covering when to use each approach. Reflection runs at runtime and supports dynamic type discovery (plugins, generic frameworks, test runners), while source generators run at compile time, producing zero runtime overhead and full NativeAOT compatibility. The guide covers performance trade-offs, AOT constraints, a feature comparison table, real-world examples with System.Text.Json and a DI library called Needlr, a hybrid strategy for production apps, and a step-by-step migration path from reflection to source generators.
Table of contents
What Reflection DoesWhat Source Generators DoFeature ComparisonWhen to Choose ReflectionWhen to Choose Source GeneratorsReal-World Example: JSON SerializationNeedlr as a Case StudyThe Hybrid Approach: Reflection at Startup, Source Generators for the Hot PathMigration Path: From Reflection to Source GeneratorsAOT Compatibility in .NET 10FAQConclusion2.4K Impressions