How: ZS posted an opening in London and I got a referral. Was contacted within a week and scheduled for a first site interview. The person leading the recruiting process was efficient, kind and friendly, providing a very nice first "official" interaction and image of the company. The rounds: A case (simpler than I expected, with easy numbers to work with, and slides with all the information needed) and a fit interview. Interviewers were friendly and knowledgeable, and clearly demonstrated an interest in the interviewee-me (especially, motivation - why ZS now, given your background). Second (and last round) involved several back to back people with a case, presentation, fit... Overall good impression of the people I interviewed with (except the person leading the fit interview in this second round that was perfunctory going through a list of questions, I was unable to turn that style into a conversation that could flow naturally--still unsure if that was on purpose or just my inability to steer the conversation). That portion of the interview raised many flags for me. Why not: It boils down to the flags raised by that interview and by the interaction with HR afterwards. One of the main attractives I found for ZS was their motto "Do the right thing". I might have been naive, but through some of my interactions with ZSers (current and former) it seemed that they indeed take that motto to heart. After dealing with HR for the offer and with a couple of the experiences from the interviewers, my impression was that ZS may still live by that motto, but maybe not in all the offices -- at least not at the current time in the office I interviewed.