I applied through an employee referral. The process took 4 months. I interviewed at Thoughtworks in Dec 2014
Interview
Started off with a few phone interviews, while they were deciding which position I might best be fit for and eventually I was invited in for an in-person interview. The interview process I went through seemed like it was for a different job than the one described to me over the phone. My take away is that this is a company that wants to build out their design staff, but doesn't have a hiring process for designers in place. When talking with my recruiter, it seemed as though this would be a 50% design and 50% business role, but when I went in for my interview, I was told it would be almost completely business analyst. I was also told that even if design work came up that would be a good fit for me, and I was already assigned on a project as a business analyst, I would not be taken off to help on the design. Since design roles coming up seemed rare already, it got the vibe that I might not be doing any design at all. I started off my interview day by talking with designers, but then my next two interviews were focused on business and how much of a business role it would be.
Overall thought: this is pretty much solely a business analyst role.
Interview questions [1]
Question 1
Business Analyst interview - they ask you to redesign a kitchen and give you two ThoughtWorks employees to act as your clients. They want you to think about the "problem" of redesigning a kitchen in a very analytical, logical, and business-like way, not at all as a designer. This was unexpected to me because, as mentioned above, I didn't understand until my values interview (which was after my business analyst interview) that about 80% of the role would be business analyst, not design. Also, I thought as my background is in design, I didn't think it would necessarily be bad to bring some design thinking in and I thought the interviewers would be more understanding of that than they were.
Work with your recruiter to understand how they are going to expect you to balance business and design in this role so that you can prepare to show the right skills in your interviews.
They also give a logic assessment, which was difficult for me as a designer, but overall not too bad - I answered about 7 of the 11 questions. The Wonderlic text (IQ test) wasn't too bad - I was nervous and only got through about 35 of 50 questions, but an average score is a 22, so I think I scored well above average. For these tests, my advice is to prepare a bit in the week or so leading up (you can find sample questions from both tests online) just so you know what to expect.