Heap Software Engineer Interview Questions
& Process

The interview process was really refreshing. All interviews were on Zoom. There were 4 tech rounds. The first round involved coding a simplified backend API for a page UI. The second was about discussing a backend technology I know well, with questions to test my depth of knowledge. The third was a system design problem related to Heap's past challenges. The fourth round focused on discussing Heap's backend platform architecture, and they evaluated the quality of my questions. Additionally, there was a 30-minute call with the CEO for a values interview. Everyone was engaged and pleasant, and the interviews assessed my grasp of distributed systems and backend engineering rather than just LeetCode problem-solving.

So the interview process had three main stages. They let me pick my programming language for everything. First was a 1-hour phone screen with two coding questions using a shared editor. Then, I had a take-home assignment that was supposed to take 2-3 hours, but they said take more time if needed, so I'd block out 4-5 hours just to be safe. This involved one main task. The last stage was a full day onsite, kicked off with a casual dinner with the CEO and a couple of engineers where we just chatted about interesting stuff, no technical stuff there, just seeing if I'd fit in. The actual day-long interview was about building the backend for a search problem. I was given a web app template and told to use Redis. They suggested I look up Redis beforehand and gave me a virtual machine with everything set up. The interview started around 11 am, I had lunch with the whole office, and then got back to coding from 1 pm to 6 pm. They'd check in occasionally to see how I was doing. I had to present my approach on a whiteboard, and they said my first try was too complicated and slow, so I had to rethink and come up with a second solution, which was better. After I finished coding, other engineers tested my application manually and pointed out bugs, mostly related to edge cases I missed. I had to explain how I'd fix them and then actually fix them. The technical part wrapped up around 6:20 pm, and then I had dinner with a bunch of Heap employees, which felt more like a 'sell' dinner, with both technical and non-technical folks. I heard back about the results pretty quickly, usually within a couple of hours after each stage. Overall, it was really well organized and felt like I was in control of the pace.

I got a message from a recruiter on A-List and set up an interview for Feb 8. On Feb 8, I had an interview with someone who seemed like a fresh grad. They gave me a good amount of time for my questions, but it was mainly to test my technical skills. I had to build an anagram function, and I did what I could. On Feb 12, I got an email saying I wasn't moving forward. Everyone was nice, but if this is how Heap interviews go, focusing only on whiteboard skills, I think they'll end up with a team that isn't very diverse in thinking or creativity.