I had 3 rounds of interviews: first one on the phone (screening), second one at their office with 2 managers, and third one as a conference call with 2 other employees. Questions were behavioural and situational. The interview was fairly easy and aligned to the experience required for the job. The only aspect that I didn't like much is that during the in-person interview the managers did not take ANY notes! I wonder if the decisions are just based on intuition (which leads to all sorts of biases....)
When you do the group test the trick is to work with the other team even though they set it up like a competition, trust me.
Basic interview questions with the addition of drug screening and physical capabilities test.
There can be a decent amount of overtime available depending on the amount of projects. Overtime is not mandatory.