Back when I was interviewed the process had two big sections.
One was a huge set of rather complex logical reasoning questions. It took me hours and a lot of effort to finish that. Felt rather exhausted in the end, but as a person that appreciates challenge - couldn't drop it half-way.
Initial feeling I had that those questions do not directly relate to work is deceptive. Logical reasoning is one of the corner stones for any programmer. Also, for mostly remote company - it's of utmost importance for people to be able to understand others and express their thoughts clearly. That set of questions tested exactly that among other things.
Being a part of the company for years - I've been able to work with every developer in the team. I can feel and clearly see the value of such interview process. It's hard, challenging, exhaustive, but hits the mark pretty well.
Then there was few hours worth practical task that tested my relevant technical skills. To be honest, that one was way easier to figure out. Haven't got anything special to say about it except it was less formal and template-y then most of the technical interviews out there in the wild. Pretty practical, on-point and without those boring "implement a bubble sort algorithm" tasks.