The hiring process is long and drawn out. You submit your résumé which then gets filtered. If yours makes it through the filter it goes to the hiring manager who then down selects and does an informal screening. It depends on the job position and manager but for most they are very informal and just helps them get a first pass to see if they even want to talk to you. Then they down select again for the formal interview. This is in person with a panel of people. I think 3 is minimum. They will ask a series of probably 4-7 questions that are situational so "when was a time when you experienced...?". Those require you to give a scenario and explain the process you went though but you won't be asked specific technical questions such as working a problem. At this point the manager either makes their final decision or could bring people in for one last round (mostly for dev positions). HR is slow and so it can take a while after the manager decides they want you to the time you get the offer.