The one I remember best was a project in C where I was a contractor. I had to take over for a guy and also build on the project to cover some new hardware. He was the company's top software engineering guy and was to go on to the next big thing the company was doing. His style was to do things quickly and then spend a lot of time debugging it. Obviously that means minimal comments in the code. He did not like to chase down compiler warnings, so he turned off warnings in the "make" scripts. He used minimal "function prototypes" because the proper ones gave him compiler errors he didn't want to resolve, etc. He knew enough C to get his stuff to work but had an "assembler orientation". I've done a lot of assembler work in my day and it was obvious. He had some assembler routines to be called by the C programs that were totally uncalled for if he knew just a bit more C.

I walked in on him in the lab one Monday morning debugging his code using a debugging tool he had never showed me. Unshaven for days and short of sleep, he was trying to resolve a severe customer problem that had come in late Friday. He was telling it looked like compiler had done something screwy with a particular statement. I looked at it and said "You know, there are a lot of operators strung together there without parentheses." "Are you sure you have the precedence rules straight in you mind?" He waved me off. Turns out that was the problem. On the plus side, he had saved a second by not typing parentheses during coding.

Flying by the seat of his pants.