JIT Compilation

Understands the difference between AOT and JIT compilation and when to use each. Knows concepts of hot path, execution profiling, deoptimization. Has studied JIT in JVM (HotSpot) or V8.

Understands the fundamentals of JIT Compilation. Applies basic practices in daily work. Follows recommendations from the team and documentation.

Implements a baseline JIT compiler for a simple bytecode format. Understands tracing JIT vs method JIT architectures. Implements basic inline caches for dynamic method calls.

Independently implements JIT Compilation. Works with IR and optimizations. Writes compiler tests.

Designs multi-tier JIT: interpreter → baseline JIT → optimizing JIT with profiling. Implements deoptimization and on-stack replacement (OSR). Profiles and optimizes JIT compilation overhead.

Designs compiler passes and optimizations with JIT Compilation. Works with type systems. Mentors the team.

Architects JIT subsystem for the language runtime platform. Makes decisions about compilation strategy, tiering policy and JIT code memory management. Manages the JIT engineering team.

Defines compiler architecture. Establishes development standards. Coordinates the compiler team.

Defines runtime compilation strategy for the platform over multiple years. Researches advanced techniques: YJIT, Cranelift, copy-and-patch compilation. Publishes JIT research.

Defines compiler/language development strategy. Designs core language features. Establishes technology vision.