I applied through an employee referral. The process took 2 months. I interviewed at Upwork (Mountain View, CA)
Interview
An initial discussion with the director on the phone. This was followed by a phone screen about a couple of weeks later with an engineer. The final round was an all day interview session at the Mountain View office. The entire process took 2-3 months to complete, but this was probably because it happened over the end of year where people were probably off on holidays.
Interview questions [1]
Question 1
The questions were mostly around algorithms fibonacci, tree traversal, sorting algorithms etc. The questions themselves were phrased typically in terms of hypothetical problems to which you would have to figure out which algorithm would be best suited to apply and explain on the whiteboard. These were then typically followed by questions around space-time complexity of the solution.