The process took 2 days. I interviewed at iRobot in Mar 2007
Interview
I contacted their HR department through a friend about a month before they called to talk. I was scheduled to come in for a day after a brief phone chat. Very straightforward technical talk, followed by a session taking apart and then re-assembling a robot on the fly, talking about the various sub components. I was hired the next day, started working the next week.
Interview questions [1]
Question 1
What is the rotational inertia of a spinning cylinder?