After submitting my application, I contacted one of their devs for coffee and to chat about Bento. A week or so later, I had a 30 minute interview with VP of Engineering in SF.
Then a one week take-home code challenge. They got back to me about a week later to let me know they were interested in doing a two-hour technical google chat (video) interview. Talked with two engineers, one in SF, one in Chicago. First were front-end questions, questions about quirky JS things, CSS and other front end things. Then a backend interview discussing structuring REST APIs, etc.
A few days later, they invited me on-site for a seven-hour interview with several folks in Chicago, as well as several in their SF office. This involved some pair-coding, white-boarding, review of my code challenge, logic puzzles, and cultural/behavioral questions.
A few days later, they asked me to speak with their CEO for around 40 minutes.