If I remember correctly, the file was processing global state from other parts of the system, and it was such a Byzantine bit of code that I had almost no hope

If I remember correctly, the file was processing global state from other parts of the system, and it was such a Byzantine bit of code that I had almost no hope of understanding what it was actually doing without being able to observe state in the production system as it was being used. Plus at the time I wasn’t a particularly competent programmer myself (this was my first programming job). In the end I figured it wasn’t worth risking breaking it when its replacement was on the way.