[barbs]

My favourite recent example was SQLite, where hundreds of micro-optimizations led to version 3.8.7 to be 50% faster than 3.7.17.

http://permalink.gmane.org/gmane.comp.db.sqlite.general/9054...

[panic]

Here's the associated HN discussion thread: https://news.ycombinator.com/item?id=8420274