Dell Technologies Senior Developer interview questions

I've found a job ad on openstack.org/jobs, I've contacted HR, and offered my services. I had a first introduction call with HR, and then we organized an interview with a manager. There been a lot of questions regarding my background. Next interview involved team leader and some developer from US. There been quite a hardcore test regarding python programming language. Later I've been sent an offer to join a company, they even give a bonus payment. I had to relocate my self from Lithuania to Dublin.

Applied online, got HR call 1 day later, phone call with hiring manager the next day. Went for the onsite 5 days after I applied. Interview lasted 4 hours (30 min slots with diff team members). Every thing was going well until one developer started asking me stupid/got-cha kind of questions that got me visibly irate which affected the rest of the interview.