I was initially contacted by a recruiter and we spoke over the phone. Everything went very smoothly, and a follow-on interview was set up with one of the engineers. That phone interview was about my experience, what I was working on currently, and why I was interested in Square. An onsite interview was set up, and they were accommodating to my schedule. I had a couple of pair programming sessions, which I thought went very well. One regarding linked lists (he gave me choice between linked lists and heap). We used their Mac systems and xCode, which i was very familiar with, so no problems there. There were even some tricks/shortcuts I knew that the interviewers did not know. After that, I met with a couple hardware guys, and the questions were pretty easy (draw a block diagram of a board you've written firmware for, explain SPI protocol). One of the hardware guys was very distracted during the interview, and appeared not to really be listening to me or "tuned in" to the interview. he seemed to be more concerned with what was going on outside the interview room. A tad rude, but meh, whatever. The recruiter came in and wrapped things up. At that point, I thought I'd done extremely well and was a great fit for their team, probably overkill for the simple firmware support they needed. The recruiter said she'd get back to me with "next steps" after discussing with the engineers. A couple weeks go by, and I reach out to the recruiter and ask how things were going. She said she'd get back to me "in the next few days". Two more weeks go by, hear nothing. Try email and calling again, no response for days. Finally I get a call and I wasn't the right fit for their team. I was glad to finally get an answer one way or the other. I felt the team was talented and the office space is great. It's a great opportunity for sure. I wish the recruiter could have been a bit more on top of things with feedback, and also provided a little bit more explanation about why the fit wasn't right. Overall, it was a decent interview experience.