I applied through an employee referral. I interviewed at ZS Associates (London, England) in Aug 2017
Interview
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.
Interview questions [1]
Question 1
Pretty standard questions - for the case just looking at numbers, what do you think would happen if we increase the number of doctors we visit by X %?
For the fit - first round was more a conversation about me and the company, past and perspectives; second round was a drill and someone (quite senior) needing to check the boxes for all the questions on the list.
Went through the typical HR call in the initial stage; I felt that the interviewer was disinterested, but still proceeded to mention that the team will schedule an interview with me by end of the week.
I followed up a week after when they initially mentioned I can anticipate to hear back from the team. The process entailed 2 stages, with the initial stage online, and the second stage in person.
Interview comprised of 5 rounds,
1) HR phone screen for role alignment
2)Technical discussion with Senior Consultant (tools, data engineering/SQL)
3)Hiring Manager round (technical + behavioral)
4)Project presentation on an end-to-end pipeline (with Senior Manager & Associate Principal)
5) Final discussion with Principal
Interview questions [1]
Question 1
Tell me about the project you worked on where you created an end-to-end data pipeline
It was very streamlined and structured. Three rounds and the first round was the most difficult one, this was followed by a case study and two rounds testing my technical capability followed by a fitment round.