Process took about a month, I applied directly from their website.
Step 1) Initial Phone Screen
Don't remember this part but i'm sure it was no biggie.
Step 2) Code Challenge
Was tasked to square an array of sorted numbers ex [1,2,3,4] and maintain order after squaring. This was simple, then while adding test cases we added negatives and this is where a mergesort was needed (or multiple pointer array implemention)
Step 3) On-Site 4 hours, 1 hour per interviewer
1 - Create a markdown to html transpiler
2 - Create a rate limiting function
3 - Talk through some previous code (sent this beforehand)
4 - Create a React UI that takes in input and hits an API and displays results
Each of the on-sites weren't that bad, I tried a Google-like approach and discussed the problem fully on a white-board but realized they could care less (maybe) because they wanted each part to be runnable.
I got each part to be runnable and near complete. Markdown transpiler was pretty much complete I just needed to add 1 more case. Rate limiting function was completed early. React UI was complete to initial requirements but we didn't get much further.
Ultimately the interview process was fun, I like being flown out now :D. Unfortunately Full-story decided to move on, all good.