I applied through an employee referral. The process took 3 months. I interviewed at 18F (Washington, DC) in Apr 2015
Interview
Difficult and thorough, they care about who they hire
Total actual interview time was about 4 hours
There was a phone screen
There were 3 in person (or virtual video) interviews around 3 main areas, which I have listed below.
Interview questions [1]
Question 1
They divided the interviews up by:
Problem Solving
Tech or Functional Expertise
Core Values