The interview process made me very hesitant about joining the company because it was strange and not well thought out. I had 7 rounds of interviews total for a mid-level engineer.

1st technical screen: This was a 1-hour coding interview. I was 90% done with the last problem when the interviewer stopped me with 5 minutes left. They then erased my work to fill in the answer themselves. Despite the interviewer having 10 years of experience in software engineering and knowing the answer, they struggled and took 20 minutes to get a working program. I then received feedback after the first round stating I passed, but the interviewer ironically commented that I struggled on the final question. Clearly, they had a hurt ego, but I passed the round, so no harm, no foul.

Next were the actual core interviews. At this point, they had me sign an NDA and informed me I had 6 more rounds.

During these interviews, I was confused about what Square was trying to achieve or learn about candidates. No one asked me a single behavioral question, about my qualifications, or even basic programming theory. Instead, it was hours of theory questions, a couple more coding questions (which were essentially repeats of the tech screen), and maybe 2 questions about my resume. Some of the theory questions were quite dated. The interviewers seemed inexperienced, as they didn't know much about other facets of the topics they were interviewing about.

It seems the only reason they make you sign the NDA is so others don't discover how much of a mess the interview process is.

It's true Square is collecting surveys to improve the interview process, and everyone talks about Square having "growing pains." However, remember they've been around and interviewing for over 10 years. It really doesn't get much better than this.

Coding Questions and Theory about programming/architecture