JITs and interpreters suck for realtime, and there's only so many optimizations that an AOT compiler can do to a Java codebase (hence why JITs ar so prevalent for Java). Pushing all of these verifications into compile time significantly reduces the run time requirements.

Honestly I see Rust as (potentially, down the road) being a better, less verbose Ada than a better C++ or Java. You tend to write Rust code much like you would an Ada or VHDL program.

Both JamaicaVM and PERC seem to have favorable requirements when run with AOT compilation, and the JIT compilation didn't seem too onerous either. What problems have you run into?

I ask because I'm in the process of spec'ing out a safety critical medical device, and JamaicaVM is the lead candidate at the moment.