10+ rounds, all 30min and 1:1. Overall a great experience and incredibly talented staff. The only disappointment was the missing guidance and feedback along the process from HR and the hiring manager. Even after 10+ rounds, I didn't get any feedback on my emails or questions on next steps. Hope I'm the exception to the rule.

Applied online, recruiter contacted and had screening call followed by a call with the hiring manager. I was then invited for an onsite interview. Once on site I was blown away by the facilities and the buzz but very discouraged by the confusion and chaos on strategy and direction. Clearly Twitter does a lot to create a cool environment - a l a Google - but without clarity of direction and a comparably profitable business model. Its like the coolness is put way before the concept of making money as a business. It seemed to me this company skews towards younger hipster type candidates with less experience but raw smarts. I was not invited for a second round. What struck me was their curiosity in getting as much out of me in terms of best practices I implemented at my existing employer, a very successful Internet company. They wanted it all, seemed a bit over the top! My biggest disappointment was they never closed the interview process to tell me I was not successful.