Wrote automated tests, chased bugs through old PHP, and shipped on a large team where ATS edge cases were the job — not the exception.
Paycom’s ATS is how large employers take applications, move candidates, and keep recruiters honest about where someone actually is. I was Software Developer III on that team. It was a large group, and it had to be: hiring workflows do not fail in one tidy way.
A lot of production was legacy PHP. I spent real time in it — debugging behavior that had been extended for years, reading code nobody wanted to own, and making changes that could not break the paths recruiters already trusted. Newer work sat in React and C# / .NET. The interesting part was not picking a stack. It was keeping both worlds coherent.
Automated tests were how we stayed sane. Playwright and Selenium against flows that only show up when a candidate, a requisition, and a recruiter disagree about state. Unique issues were normal: applications that forked, statuses that lied, edge cases nobody wrote down until a client hit them.
I translated hiring requirements into shipping software, reviewed code, and fixed defects on a team big enough that communication and tests mattered as much as the line of code. I am not going to inventory every internal feature here. The work was tracking people through a hiring machine.