Initial phone interview with HR for personality fit was fairly standard. Was asked to interview in person. Interviewed at their Boston office with 3 different groups of people.
First group was a set of developers, whom I did not have a lot of time to talk with as they were waiting for an important call with a client. They described what I would be doing briefly, and if I recall correctly, did not ask any important technical questions.
Second group was another set of developers (I think Front and Back-end?) who described the internship a little better. Asked what I had experience in and asked about a few of my projects and skills, but nothing super technical.
Third group consisted of the CEO, CTO, and a Software Engineer. Basically asked about my background, why I wanted the internship, asked about previous projects and courses I've taken, and some general questions to see if I would be a good fit for the requirements for the position (e.g. "Do you have any customer service experience?" etc). This group was the most engaging and the most enjoyable to talk to.
Got a tour of the place and overall left with a positive experience. I thought I did well, but I didn't end up getting the position.