Native AOT: The End of JIT

Usually, .NET compiles your code into "Intermediate Language" (IL), which the JIT then compiles to machine code at runtime. Native AOT compiles everything to a single, small, highly-optimized machine binary BEFORE you deploy.

1. Why Native AOT?

• Instant Startup: No "Cold Start" or JIT compilation delay. Perfect for AWS Lambda and Azure Functions.
• Small Footprint: Docker images can be 80% smaller because you don't need to ship the full .NET Runtime.
• Security: There is no IL code to 'Decompile', making it harder for hackers to reverse-engineer your app.

2. The Trade-off (Reflection)

Native AOT does not support "Dynamic" programming. You cannot use System.Reflection to find types at runtime because there is no 'Runtime Type Information' in the binary. You must use **Source Generators** instead.

4. Interview Mastery

Q: "When is Native AOT a BAD choice?"

Architect Answer: "I wouldn't use it for massive monoliths that rely on legacy libraries with reflection (like old ORMs or Serializers). I also wouldn't use it if I need 'Hot Swapping' of plugins. Native AOT is best for **Microservices**, **CLIs**, and **Edge computing** where startup speed and memory efficiency are more important than dynamic flexibility."