> prioritise memorising docs and single line solutions

This is actually toxic to long-term best practices for a business whose intellectual property is stored as source code. Source code is for humans to read, and so one-lining it into a very clever but obscure invocation is costly in two ways: it costs the writer time & effort to "compress" it, and then it costs every maintainer time & effort to "decompress" it. Five well-commented lines of code that have clear variable names are superior -- from a business case, and a security case -- than one line. In most scripting languages those one-liners compile (hand-wave, whatever) to the same machine code as the five good lines, so there's typically no performance difference.

> claims they hire the top 3%

They hire 3% of candidates, so obviously it's the top 3%, and not an arbitrary slice of the candidate pool filtered by their bogus biases, right? I'm a hiring manager and this interview process sounds totally garbage. I suspect they have no data that correlate their interview process to productivity on the job.