The interview took place in multiple stages. It was separated into four different interviews plus a take home project (might have done interview style if not for covid.) The first interview was just a "seeing if you're a good fit", which is pretty easy if you feel comfortable talking about the things you're into that may relate to the job, excitement helps to get the callback. The second interview was a brief description of the project you'll be taking home. You have a day to complete it but it should only take you an hour or so if you know what you're doing. After that, the software engineering team goes over your code with you and asks about your reasons for designing it the ways you did, so make sure to have answers for that. After passing that, you move onto a final interview with a higher-up about the significance of the program and what working at AT&T looks like. From there you wait for your phone call. They called me back about two days after I had my last interview but your mileage may vary.