The interview process consists of two stages. First one is behavioral interview, It's generally face to face and consists of general open ended questions due to which you can relate it to any situations.It lasted for over an hour. Tip 1: don't be in a hurry to answer, take your time and think it through.
In my case, I didn't hear back from Cummins for over a month and just when I almost gave up hope, I received an email for the second round (technical). I was rather apprehensive about this telephonic round and did some preparation. The interview lasted for around 40 minutes and was more inclined towards behavioral. Tip 2: Know everything mentioned in your resume, especially if you have done any projects. From my experience, it wasn't too technical but this depends on who is conducting your interview and their field of expertise.
Overall its a great experience, feel free to ask them questions in the end and I would suggest doing that as it shows that you are interested in learning more.