I attended a career fair, took their handwritten coding assessment, and talked to an engineer. I attended a dinner and received an interview the same week. I can't overstate how well Duo treats their employees and candidates. First, they offered me all the teams available to interns over the Summer to which I could pick. Then, they flew me out to Ann Arbor to meet the teams, set up phone calls with managers, connected me to previous interns via email and over the phone, and my recruiter regularly connected with me through text. In fact, they were setting up a Halloween party on the day I visited their office, which was really neat. Not many companies will go through the hassle and extra work for one candidate, but it really provided a better view of the company in my eyes. They are connected to top talent from all across the United States, are one of the most exciting startups at the moment (especially in security), and innovate across several different fronts through their engineering teams and research labs. Opportunities are abundant and software engineers have a lot of freedom in a highly productive environment with a chill vibe. My reason for declining the offer wasn't because the company has a flaw. It was simply a matter of opportunity at other companies to focus specifically on my field of computer science. If I wanted to just do any kind of software engineering, I would've accepted the offer in a heartbeat. Similarly, if Duo intersected the field of security with my field of interest, I would have accepted immediately as well. They are truly a fantastic company and they could not have done anything more in their attempt to persuade me. I highly recommend the company to anybody else in the interview process because their culture is amazing, their teams have interesting projects, the people are top notch, they'll really push you as an individual, and they are bound to enjoy even more success in the near future. I can't say much else to make them sound any better. I can tell it's a fantastic company to work for.