So according to the recent talk Reflections on Haskell@Meta by Simon Marlow, Haskell is no longer used in Meta (Facebook, Instagram, ...) as the main language to specify automated moderation tools. Instead, they use Hack, their version of PHP.

As Simon explains in the talk, the decision to drop Haskell was made whilst knowing that many of Haskell safety guarantees will have to be dropped in the new system. I wonder if we should now expect to see many more unexpected moderation missteps in the coming years 🙂.