I'm really sorry to say this but you're spreading FUD 1. slack backend is written in php and other big companies. 2. php is actually faster than python/ruby 3.

I'm really sorry to say this but you're spreading FUD 1. slack backend is written in php and other big companies. 2. php is actually faster than python/ruby 3. opcache in production (which is both simple to activate AND a well-known best practices among people doing php professionally) eliminate the performance hit you will get. 4. your backend language performance is often far from being the bottleneck in most endpoint where performance do matters , it's often either a database optimization problem, an algorithm problem or a really CPU intensive tasks that you will offload to a dedicated library written in C. I perfectly understand PHP does have a lot of flaws, but production performance is not one.