The web codebase was once written in PHP, but they moved away from that a decade...

rafark · on July 6, 2023

It’s still very similar to php. Same syntax, same execution model. If you look at some hack snippets you would think it’s php (because it mostly is).

Switching from hack to php and viceversa should be extremely easy.

That being said, they chose python because Instagram is written in python, they are probably using a lot of existing libraries.

goykasi · on July 6, 2023

That wouldn't even make sense. They created hack/hhvm to scale and optimize the platform and codebase. Taking a step backwards and refactoring (hack != php now) would be a horrible idea.