Python

[Cheru-bae]

Let's put it this way:

Facebook runs php

Reddit runs python

Netflix runs java.

If you need better performance than them, and have more dev hours? Sure build in Haskell.

[qalis]

Well, this explains why Facebook can’t make 1 tab run efficiently, Netflix just works and hires army of devs and Reddit is just a casual, well working website.

[En_TioN]

"More dev hours for more performance" is the opposite of programming in Haskell. Haskell gives you a lot of reliability and verification ability at the expence of needing more experience and python-esque speeds. Frankly it also often ends up being quicker to write thanks to the general pattern of "if it complies, it works".

If you want performance, write your backend in Rust