dealing with code written by scientists who are bad at programming? obnoxious at worst. generally simple enough that you're better off rewriting most of it.
dealing with code written by scientists who are good at programming? absolutely terrifying. you are presented with a hundred thousand lines of python code written by someone who has no formal training and whose first programming experience was teaching themselves fortran 77 on an old mainframe computer. not a single good practice convention is followed. unreadable syntax tricks you've never seen before are used to save like two or three lines here and there. there are absolutely arcane performance optimizations that have never been seen outside of like one paper published in the 90s and make the program like 5% faster. there's also freshman CS student level optimizations that they completely missed. there is basically no documentation. you are left to learn how it works with the source code and a dozen examples which have maybe three or four comments between them. good luck. may god save your soul.
