I had a single technical phone screen with the hiring manager for an OS development role. The interview started with questions about my OS dev experience and knowledge of internals.

For context, I’m a Linux kernel contributor, regularly patch OpenWRT, have formal training from the Linux Foundation in kernel development, and contribute to SerenityOS, an open-source x86 hobbyist OS. So, OS development is definitely in my wheelhouse.

Then he asked, “What happens when you call malloc?”

Perfect, I dove into the technical details—explaining how it’s handled by libc, potentially calling sbrk() or mmap(), trapping into kernel space, with the MMU mapping pages, and possibly involving the page fault handler. It’s an OS dev interview, so I went into the nitty-gritty.

But he cut me off, kept repeating, “No, what happens when you call malloc?” without any further clarification. It felt like he was looking for a much simpler answer—maybe something like “you get a pointer to memory”—but I was genuinely confused given the technical nature of the role. This was a position for OS internals. The communication just wasn’t there, and it made the whole conversation feel frustrating.

Curious about the interviewer's background, I checked his LinkedIn afterward. Turns out he’s been with Intel for over two decades. Maybe that explains some of the disconnect—a bit rusty after lounging at a single company for your entire career.

Then, out of nowhere, I was told that if hired, I’d have to stop contributing to open-source projects. That was a deal-breaker for me, especially in a field like OS development where open-source contributions are so valuable.

Overall, it was a very odd experience; the entire thing felt like a fever dream.

OS internals, syscalls, kernel development