The Reflection Wall

The Core Problem

For 15 years, the .NET ecosystem's testing tools have relied on runtime reflection (System.Reflection.Emit) to generate mock objects dynamically. This creates a fundamental incompatibility with modern compute paradigms.

What is the Reflection Wall?

The Reflection Wall is the barrier that prevents organizations from adopting Native AOT (Ahead-of-Time compilation) while maintaining testable code.

How it Works

1. Legacy mocking (Moq, NSubstitute, FakeItEasy) uses System.Reflection.Emit to generate proxy classes at runtime
2. These proxies require a JIT compiler to compile IL (Intermediate Language) into machine code on the fly
3. Native AOT compiles everything to machine code before execution — there is no JIT at runtime
4. When legacy mocks try to emit IL in an AOT binary -- crash

The Impossible Choice

CTOs are forced to choose:

Option	Benefit	Cost
Adopt Native AOT	Lower cloud costs, faster startup	Lose testability (mocking breaks)
Keep JIT	Maintain test infrastructure	Higher cloud costs, slower startup

Skugga's Solution

Skugga breaks through the Reflection Wall by moving mocking from runtime to compile-time:

• No Reflection.Emit -- Mocks are Roslyn-generated C# classes
• No JIT required -- Generated code compiles directly to native machine code
• No dynamic proxies -- Standard static classes with interface implementations

The result: organizations can adopt both Native AOT and comprehensive testing.

Impact

Metric	With Reflection Wall	Without (Skugga)
AOT Compatible	No	Yes
Cold Start	~476ms	72ms (6.6x faster)
Container Size	~200 MB	47 MB (4x smaller)
CPU Efficiency	Baseline	5.1x better