Test First is Not Optional

Some agile teams do well. Many don't. In my experience, there is one consistent thing that separates the teams that succeed from those that fail and that is sound engineering practices. Foremost among those sound practices is Test First (or Test Driven) design.

Having a solid test suite that runs frequently is a key to agility. By frequently I mean every night at least. Without frequent regression testing, teams become risk averse and unwilling to make changes in case something breaks. In an agile environment where change is encouraged, this can be a death sentence for an agile project.