Reddit ran away from lisp as fast as it could once the original goal of using the language (to secure funding from YCombinator) had been met.

Reddit apparently ran away from Lisp primarily because all the servers ran on FreeBSD while development ran on Macs and because at the time they were forced to use different Common Lisp implementations (OpenMCL on Mac and CMUCL on FreeBSD) so they couldn't even test what they were deploying, essentially. Today with SBCL that wouldn't have been an issue.

Right, today there would be some other issue.

Don't be so sure. People who want to develop and sort-of-test with one stack, and then deploy on another, will find a way to do it in 2023.

I don't think that's an accurate representation.

They were merged with another company. Reddit guys knew both Lisp and Python. Other company coders only knew Python.

Since then, they've had massive issues scaling Python in general and their ORM dependence in particular.

I've been on reddit since the beginning when it was effectively a lisp-weenie site (clued into its existence by pg (discovered via his blub essay)).

It migrated to python very early in the game (via Aaron Swartz (rip)), and it's my understanding that it was that move that allowed them to scale it.