There are times when reading the code is necessary, but oh boy are LLMs so much faster at finding the part of the codebase I want to read.

Several projects I work on call into or interact with gigantic codebases. A couple years ago I would have to allocate 30 minutes some times to either trace through the code base or setup and attach a debugger to step through the code until I found the part I needed to know about.

Now I send an LLM to go find it and it comes back with a list of files and line numbers in minutes.

It’s still not perfect. I had a codebase walk this morning where even GPT-5.5 extra high failed to find something I knew was in there on the first pass. It got it with some more directed prompting. If you delegate trust 100% to an LLM you will get bit eventually.