The process started with the recruiter getting back via email to set up the online skills test. This was followed by a phone screen with an engineer, going through a sample problem in ADT design. The in-person interview was with (if I remember correctly) three engineers and the CTO, in sequence, and primarily focused on more problem solving. I found the process a lot of fun; the questions were interesting, and just the right level of complexity to work through in the individual sessions. There was time in each session to ask questions back, which was especially productive with the CTO, as you might expect. Everyone involved was friendly, professional, and smart. This was the best interview process I've seen in several years, and so I was delighted to accept their offer. My initial impressions from the interview have been born out on the job, too: everyone is still friendly, professional, and smart.

Describe how you would write a function to draw a circle (given a function to turn on an individual pixel).