<a href="https://developers.google.com/web/fundamentals/performance/rendering/simplify-paint-complexity-and-reduce-paint-areas?hl=en" rel="nofollow">https://developers.google.com/web/fundamentals/performance/r...</a> and <a href="https://developers.google.com/web/fundamentals/performance/rendering/stick-to-compositor-only-properties-and-manage-layer-count?hl=en" rel="nofollow">https://developers.google.com/web/fundamentals/performance/r...</a> are very Chrome-specific advice. A different rendering pipeline will not suffer from these performance gotchas. IMHO, the distinction between "painting" and "compositing", where painting is hugely more expensive, is an artifact of browsers' dependence on suboptimally-performing GPU-assisted (as opposed to GPU-accelerated) vector graphics pipelines [1].<p>> Want a definitive list of which CSS properties trigger layout, paint, or composite? Check out CSS Triggers.<p>More overly-Chrome-specific advice. This list of properties varies from browser to browser, and a browser that has off-main-thread layout and/or a unified vector graphics pipeline will not have these gotchas.<p>> In any case, whether you choose Flexbox or not, you should still try and avoid triggering layout altogether during high pressure points of your application!<p>Chrome-specific advice again (although, to be fair, this applies to all popular browsers right now). This doesn't apply if your layout is off the main thread.<p>> If you really want to see JIT in action you should check out IRHydra2 by Vyacheslav Egorov. It shows the intermediate state of JavaScript code when Chrome’s JavaScript engine, V8, is optimizing it.<p>It's strange to advocate using this and later on to suggest avoiding microbenchmarking JavaScript. In any case, using IRHydra will tune your application to V8, which is a constantly shifting target and is well known for having lots of slow paths that don't necessarily apply to other engines (try/catch leading to a deoptimization being perhaps the most well-known example).<p>[1]: <a href="http://developer.download.nvidia.com/devzone/devcenter/gamegraphics/files/opengl/gpupathrender.pdf" rel="nofollow">http://developer.download.nvidia.com/devzone/devcenter/gameg...</a>