The interview process was lengthy. It started with filling out a questionnaire and doing a coding assignment. Once those were reviewed they scheduled a 30 minute phone interview. The phone interview contained mostly HR type questions with a 'tech-spin' if you will. Then they brought me to the San Francisco office for a 3 day interview. This was very intensive and consisted of one-on-one interviews, giving short presentations, and working with current engineers to extend the code that you previously submitted. Everyone was very nice, friendly, and helpful but were also very serious about understanding your skill-set and if you would personally be a good fit for the company.