For the most part, the interview process was like most other companies, but with a lot more testing.
An initial email with a screener to make sure you are really interested in 80% travel, tell you a little about expectations, and to set up first phone interview.
A phone interview with a team member to check your personality and skills. This person will stay with you throughout the process.
A tech phone interview with a lead developer to check your personality and skills.
A coding exercise which you have 3 days to deliver. You pick from 3 exercises, and must include testing and auto-build. Someone reviews your code, and then you receive a date for the onsite interview.
An online personality test that you take prior to your onsite interview. They send this to you after your onsite interview is scheduled and you must complete prior to the onsite interview.
The onsite interview consists of more tests. You sit with another developer to go over your coding exercise, and you have 1:1 interviews.
The last step for me was a call from the Recruiter saying the position I fit into has a salary range well below my current salary. Since I am not willing to take less than my current salary, this ended my interview process.
Prior to applying, be sure you are really interested in 80% travel. I was asked this in every interview. I was told that in some situations the travel is 100%.
Make sure you read their website many times from beginning to end. You will get asked questions about what you found on the website.
Also, make sure you are well rested prior to your onsite interview.
During one of my interviews, I was asked if I knew that ThoughtWorks was against the US Military and did not support our troops. In my research of ThoughtWorks, I came across one mention of this.
Prior to your interviews, read their blogs. You are given the names of your interviewers prior to the interview. Mention something about what you read. They will respond happily to you and it helps ease the tension.
For all interview situations, make sure you ask questions when they ask you if you have any questions.