I applied in-person. I interviewed at Defense Advanced Research Projects Agency (Arlington, VA)
Interview
There was no job requisition for a Program Manager job. I was collaborating with another PM and had a meeting with them and their boss. Kind of off hand, the boss said something like "well, if you're ever interested in coming to DARPA...". I immediately said yes and the next step was to generally talk about what I would want to do at DARPA.
Interview questions [1]
Question 1
What technology would you want to pursue at DARPA?