they almost certainly ask coding/technical questions. the people doing this work are far beyond being gatekept by leetcode

leetcode is like HN’s “DEI” - something they want to blame everything on

they recruit from top Computer Science programs, the top of the class MS and PhD students

what is leetcode

a style of coding challenges asked in interviews for software engineers, generally focused on algorithmic thinking

It’s also known for being not reflective of the actual work that most companies do, especially the companies that use it.

I've recently ended an internship for my bachelor at the Italian research Council where I had to deal with federated learning, and it was hard as well for my researchers supervisors. However, I sort of did a good job. I'm fairly sure I wouldn't be able to solve many leetcode exercises, since it's something that I've never had to deal with aside from university tasks... And I made a few side projects for myself as well

leetcode.com - If you interview at Meta, these are the questions they'll ask you

Did you read the tweet? It doesn't sound that way to me. They hire specialized talent (note especially the "Know-It-All" part)

Deepseek team is mostly quants from my understanding which explains why they were able to pull this off. Some of the best coders I’ve met have been quants.