/dev/world 2026

Looking for Trouble

For developers, writing code is near-synonymous with writing bugs. So we write tests. Some of us write them before the "real" code; others after. Few of us write enough. Your unit tests check the inputs and combinations you thought of in the moment. The bugs that ship are the ones that you didn’t, and the real tricky ones can lurk in a dark corner for years, escaping notice. Testing is a search problem. A bug hunt. But few of us treat it that way, testing boundary conditions and unlikely combinations as a matter of course. What if you could do that systematically? I’ve spent the last year finding out, creating a Swift testing library combining the most effective search strategies into sweeps covering stateless and stateful code. Join me as we go hunting for bugs in production code.

About the presenter

Chris Kolbu is a lead iOS/macOS developer who has been working in this space for over a decade. He cares deeply about accessibility, user and developer experience, software testing, and performance. He (still) does not care for Christmas being in summer, but is getting used to it.