I applied September 17th and assumed they weren't interested when there was no response within a couple of weeks.

On Oct 27th I was emailed and given a coding assignment involving designing a job queue to process an event stream in real time.

Next, on Nov 6th, I got an intro call with someone from HR.

On Nov 9th I had a technical interview via Hangouts and Etherpad which took about an hour. The questions were more "how would you approach this problem?" than "code a solution right now."

On Nov 30th I had two more interviews with data science team members via Hangouts. These were "see if we like you and you seem like a good fit for the team" interviews.

Finally, on Dec 10th I had a Hangouts interview with the team lead.

I received a rejection email on Jan 4th; almost four months for the whole interview process!

HR called two days later to follow up. They told me they had marked my resume for future talent searches. It was definitely the nicest rejection I've ever received.

I got the sense they have some organizational problems, which seems pretty standard for non-profits.

How would you sort a list of numbers that won't fit in memory?