Testing

As software development feedback loops accelerate toward minutes, quality assurance remains the final bottleneck where human judgment is still required.

An experiment in using AI code agents to write all the missing unit tests for an existing codebase. Let’s take code coverage to 100%.

In my line of work, I see a lot of legacy code – products that were built so fast the foundations are weak. Every little change causes something else to break. The industry standard way to stabilise such a codebase has always been test automation. But writing unit tests takes time, and in the rush of shipping features, that time is often dedicated to anything but tests. As the product expands and the code gets ever more complex, this lack of tests becomes a painful problem. If small changes break the system, sweeping changes are downright scary. The team gets paralysed. ...