Typically a slow process but only one interview for anything below a GS-13. Will take a while to hear back after having a phone interview but typically the actual interview is a panel of supervisors with very simple questions looking for how you fare in different situations.

I applied online via USA jobs in December. Got a call a month later in January looking to set up a virtual interview with 3 members of the team. Interview process was straightforward - they asked me 9 questions about working with data & my past experience. I thought the interview went well but I did not hear back from anyone for many weeks. About 3 weeks after my interview I emailed the main person who called me originally & asked for an update, no response. A week later, emailed another person who was on the panel for an update & the original person emailed me back saying they were still going over materials. Never heard from them again after that. Had to find out through the USA jobs portal that they picked someone else. Really rude to just leave someone hanging like that.