Initial half hour phone call with tech lead, followed a month later by a full interview. First was a half hour discussion with the hiring manager, then a 90 minute technical presentation with questions, then a break, then two 45 minute technical panels with various teams in the unit. This was for a position that requires a PhD, so the only challenging questions were about my own presentation. The rest of the time we discussed what I might be doing in the position. Received an offer the same day.