Confusing legacy codebase, totally stuck, no one can help, what do I do?
I'm tasked with a complicated bug fix within a massive legacy codebase that is dependency hell with undocumented spaghetti code. I've been debugging an issue for a few days and have absolutely no idea what to do next. I don't understand the code and no one else does either. I asked my lead what to do and he said to set breakpoints and read the code. I asked where. He said doesn't know.
I've been systematically debugging the issue using every technique I could find on Stack Overflow and books like Code Complete/Debugging. Logs doesn't indicate any useful information. There are no error messages or exceptions. There are no unit tests. All the domain experts I could possibly ask have left. Basically there's no one to help, reading the code and debugging isn't giving me any meaningful data points. I have a general idea what's wrong and where it's happening but my mental model of the application is still weak and things just aren't clicking. I'm super frustrated and feel stuck. I'm also in the middle of a job search and feel like a totally incompetent dev who deserves to rot here for life.
TC: 95k. YOE: 2