The process overall is very interesting though very secretive. Don't tell people you've applied or that you're being interviewed; trust me, it brings attention that you don't want.
Applied in Feb and took my online tests a few days later (challenging). Did first phone interview in March. In-person interview in DC a few weeks later.
A mix of one-one interviews and group assessments, took about 6 hours. Fairly standard questions, received my conditional offer 3 days later. Was sent tons of paperwork to fill out, and all had to be perfect. Two months later did another phone interview. Two weeks I got a letter saying my offer was rescinded. They didn't explain why, but said it was on their end. I will have to re-apply in one year.