I had 5 total interviews, but they were never more than a day or 2 apart. From interview #1 to offer, it was 3 weeks. Despite being job interviews, they always also just felt like conversations, so I left each one feeling really comfortable. TDX wants to make sure that you're not only a good job fit, but also a good fit based on personality and culture, and a genuine, relaxed conversation is the best way to judge that.