The title of this article is a variation on a theme from Extreme Programming (XP). XP is a code-centric discipline for getting software done right, on time, within budget, while having fun along the way. Quit laughing. The XP approach is to take the best software practices to the extreme.

For example, if code reviews are good, then code should be reviewed constantly, even as it's written, hence the XP practice of Pair Programming, where all code is written by two developers sharing a single workstation. One programmer pilots the keyboard while the other watches to catch mistakes and gives strategic guidance - then they switch roles as needed. The next day they may pair up with other folks. Likewise, if testing is good, then all tests should be automated and run many times per day.

An ever-growing suite of unit tests should be executed whenever you create or modify any function, to ensure that the system is still stable.