Applied online then 2 weeks later got a phone call from a lady at HR to set up a 15 min pre-screen phone interview. The pre-screen interview consisted of mostly behavioral questions and questions about the projects you've worked on and certain situations you had to overcome etc. Then 2 weeks later received an email from the Hiring Manager of the Matrex program to set up a Facetime/Skype interview. The interview lasted about an hour and consisted of various questions including the same behavioral questions the lady at HR asked. I think my interview went pretty well but I guess my lack of relevant internship experience played a factor into not being selected. One thing I didn't like about AT&T is that there is hardly no communication or follow up with their candidates. They do not keep you updated with your status and the process is extremely long. But if you do get through it, it is definitely worth the hassle because its a great company with unlimited opportunities and great benefits.