When you replace or significantly modify components of a larger system, too frequently we focus on whether the code we are building functions correctly. This is important, but it’s also short-sighted. It’s easy to introduce errors because we are changing interactions. Coding bugs are only one quality problem.

Testers today need to look more like developers than users. Automation is becoming essential, so understanding at least basic programming is a must. As companies adopt agile and deliver more frequently, modern testers should learn to code, understand continuous integration, and use tools to eliminate constraints.

When automated tests work perfectly one day but fail for no discernible reason the next, it's easy to get frustrated with automation. But you don't have to stay in the dark. Many of the tools we use today allow us to extend their reach with some custom code. Just use some systems thinking and a little imagination.