OneSignal Software Engineer Interview Questions
& Process

The interview process was split into several steps. First, I had a phone call with a recruiter where we talked about my experience and what OneSignal was looking for. Next, I had a call with one of the engineering managers. We spoke for about an hour and covered my background, the kind of work I'm interested in, and what I'd be looking for in a role. After that, I was invited to two technical interviews. These were more hands-on — I was asked to share my screen and work through a coding challenge or task that was given at the start of each session. I didn’t know exactly what the tasks would be ahead of time, but I was told the general area they’d focus on (like front-end or in-memory databases), which helped me prepare a bit. The final stage was a “virtual onsite.” I had the option to do it remotely and split it over two days, which was really convenient. It involved a series of interviews with different team members from engineering, product and HR. Everyone I spoke to was friendly, and the interview challenges were clearly explained. Throughout the process, the recruiter regularly checked in to see how things were going and was happy to adjust the pace of the interviews based on my schedule, which I really appreciated.

I was contacted by a recruiter from OneSignal. The whole process was pretty fast, about 3 weeks from the initial call to the onsite interviews. Instead of focusing too much on coding skills during the phone interview, they prefer to discuss your experience and go over your projects. I actually think this is better than doing algorithm questions early on, because they really want to understand who you are and what you've done in your past roles. If your resume is accurate, you should do fine in this round. For the onsite interviews, you'll meet a bunch of experienced engineers and company leaders. Don't stress about being a LeetCode master; focus on deeply understanding the technologies you claim to know. Their interview approach is quite different from big tech companies like Facebook, Google, or Amazon. While problem-solving is important, being a good team player is also a major factor. The onsite interviews felt more like a collaborative pair-programming session. Perfection isn't the goal; showing your thought process and how you tackle problems is. If you're into collaborative teamwork, a supportive team environment, growing with your colleagues, and enjoy wearing multiple hats, you should definitely consider applying and just be yourself.

The interview process started with a sourcing call where the recruiter was quite late but very pleasant and energetic. The call was productive, but then there was silence for over a week. Next was a multi-stage coding challenge. The hiring manager then postponed and rescheduled, which dragged out the process. During the on-camera interview, the hiring manager seemed disinterested and distracted, though I felt the STAR-format conversation went okay. I got a generic rejection email later without any explanation or way to follow up, which felt like a waste of time.