Comment by lenkite

When I was a junior developer working in the outsourcing industry, I regularly had to maintain projects where the entire codebase was in a few major functions. It was a stressful nightmare to debug - such projects destroyed my health. No feature could be developed without extensive forking of the codebase and prototyping to see what works and what doesn't.

After several such bad experiences, I religiously incorporated my personal guideline of functions never crossing the upper limit of 100 lines - with some 1 in 10k exceptions like in the parsing domain or state machine dispatch. Short functions also heavily aid in unit testing.

The only folks who believe in big functions are developers who haven't been exposed to large quantities of other people's shoddy code as a significant fraction of their working career. Once you have been through several such nightmares, you will worship small functions.