Hatch (Menlo Park, CA) Software Engineer Interview Questions
& Process

The first step was a recruiter call to check my background, experience, and interests, and they also explained the product and company. The next step was a take-home exercise. It involved a system with two pushbuttons and a small display. I had to "stub out" display hardware calls and assume an external state machine handled input events. I created a state machine for button events and display events. They also wanted to see my approach to unit testing, so I made the stubbed calls abstract functions, allowing them to be linked with either RTOS code or a unit test harness. Although it didn't need to compile, I made it do so. I provided a script to build and run the tests on Linux. I also included working code for ESP32 with Zephyr or FreeRTOS in a separate directory, as a full implementation wasn't required. I tested it on hardware. I submitted the code via a private GitHub repo, giving the interviewer collaborator access. I expected the next step to be a live interview to discuss the code, trade-offs, edge cases, and my design/test philosophy. After a week of no response, I inquired about discussing the submission. They replied that the team decided not to proceed, stating they were looking for candidates with more technical depth and system design approach, which I found confusing given the exercise's limited scope. It felt like a waste of time due to an unclear take-home exercise with implicit expectations.

It was a good experience, the interviewers were nice and seemed to really value my background, which was better than some other places I've interviewed. The process involved an initial call with the recruiter, followed by a chat with the hiring manager, then a take-home assignment. After that, two engineers reviewed the take-home test during a platform interview, and the manager conducted a systems interview.

Just a heads-up, companies sometimes forget that candidates get to check them out too. It felt like the people I interacted with weren't that engaged, and things moved pretty slowly. Whatever time you put into the take-home project, don't expect it to be really valued or respected. I'm keeping things a bit vague to stay anonymous. How a company treats people interviewing can seriously mess with its reputation. From my experience, I wouldn't really recommend their products to anyone I know. This is what happens when companies don't bother treating candidates like actual humans.