JS JITs are wonders of modern engineering, for sure. But there's a weird paradox in that as they get smarter, it doesn't get easier to write optimized code, it

JS JITs are wonders of modern engineering, for sure. But there's a weird paradox in that as they get smarter, it doesn't get easier to write optimized code, it actually gets harder! Nobody really understands how to write optimizable code. Nor, in some sense, should they. But I think there's a real need for subset languages with more predictable performance models than JavaScript, that have compilers tuned for the kinds of optimization done by modern JS engines. One nice description of this general problem was by Slava Egorov: http://blog.mrale.ph/post/12396216081/the-trap-of-the-performance-sweet-spot http://blog.mrale.ph/post/12396216081/the-trap-of-the-perfor...