Exa Corporation Interview Questions
& Process

The interview process took over 1.5 months, even going past the internship's intended start date. It was surprisingly fast-paced given they were eager to hire. It started with a phone screening, then an hour-long WebEx with over a dozen engineers where I had to present my work. Afterward, they asked for references, and it was wild they contacted all 3-4 for a temporary intern role. A week later, a manager called unexpectedly since they missed my WebEx presentation and I was interviewed over the phone. Later that day, they called again, super impressed, and said HR would contact me the next week to sort out the start date. I had made requests about timing and duration, and they were really flexible – it felt like an unofficial offer. But then, no word from HR. The same manager called at a weird time, thanked me for my interest, and said they were going with other candidates. They really wasted time interviewing for a temporary role and especially my time by offering then pulling it back for no clear reason!

The whole thing took about 2.5 months from the first chat, partly because I was busy and partly because of the holidays in Nov/Dec. Started with a phone call from the director of software engineering, asking about my background and giving me an algorithm problem. Then there was a take-home test on computational geometry that I had 48 hours to complete. After that, I spoke with the VP of software engineering over the phone for about an hour, covering MPI, C++, and my past work. The final stage was a full day onsite. It kicked off with me giving a 1-hour presentation on my previous work or research. Then I had one-on-one interviews with 9 different people, each about 45 minutes long. I expected some questions about work culture and general behavioral stuff, but honestly, every single interview was super technical. They grilled me on C++, MPI, algorithms, spotting code errors, writing pseudo code, and even fluid dynamics and numerical methods. It was a lot, but also pretty cool. They clearly put a ton of thought into designing this interview process, almost like they wanted to show off their team's expertise. I did get to ask them a bunch of questions about the work and their culture too.

I applied online and then had a call with the HR manager to talk about when I'm free and ask some basic questions. A couple days later, the Hiring Manager called me. We talked for about an hour, and they asked me technical questions. They also said I could email them answers to any I didn't get right or only partially answered. After that, I was invited to HQ in Burlington, MA for a full day of interviews. It started with an hour presentation on my PhD research. Then I met with about 6 people from the Physics R&D team, including physicists, mathematicians, and senior researchers who had engineering and software backgrounds.

So there were 2 rounds. The first round was a group interview with about 3-4 interviewers. They asked more soft skill questions and about my academic and previous work experience. The second round was technical and usually with the technical director, where I had to solve aerodynamics problems using basic principles.