First round was a phone screening, where I was asked to walk through my resume and explain my interest in digital marketing. Very straightforward and laid-back; no tricky questions at this stage.
Very soon after, I was contacted to schedule my 'first round interview'. Due to distance, this was conducted online which was very convenient. Audio quality and video feed were both fine. First I spoke again with the original interviewer, who explained paid search and answered any questions I had. Then, two team leaders were brought in to similarly answer questions and ask about my experiences. I then had to answer two "brain teasers"- one relating to a numeric pattern, the other was one of those "How many ___ are in ___" questions (where the correctness of your answer doesn't matter, but the way that you reach your conclusion does). Overall this wasn't very stressful, though being on webcam made it a bit awkward.
About a week later, I was contacted to schedule a final, on-location interview at the office. Parking was easy, check-in was fine. Briefly walked around the office then went into a conference room with two directors. Very casual Q&A, then I was given a more math-intensive ROI question for which I had to make an A or B decision, doing calculations on a dry erase board. This was a bit nerve-wracking but not traumatic by any means.
The next day, I was contacted requesting professional references, and a few days later I received a call letting me know about my offer of employment.
Overall, the follow-up after each round was extremely quick which was nice, though I don't know if this is the norm.