Introducing Cofactor

The bugs that embarrass you most are never the hard ones. They're the dumb ones. Last year we shipped a checkout button that did nothing after someone cleaned up a stylesheet, and a signup form that stayed broken in Safari for three days before a customer told us. Nobody wrote a clever bug. We just stopped looking.

That turns out to be the whole problem, and AI made it worse. When you wrote code by hand the writing was slow, and the slowness did something useful: it made you look at the code. You can't type a function without reading it. We don't type much anymore. We describe what we want, a model writes it, and we skim. The looking is the part we cut, and the looking is where the bugs used to die.

So the obvious thing to build is a machine that looks. That's Cofactor. It opens your app and uses it, the way you would if you had the patience to do it on every commit. It clicks the buttons. It fills in the forms. It tells you when something that worked yesterday stopped.

You can run it three ways, and I'd use all of them: in your terminal while you're still writing the thing, on each pull request so it only checks what you changed, and on a schedule so the slow rot turns up too. The part I care about most is boring. It doesn't break when you rename a button. If you've ever maintained a test suite you know why that matters. A suite that cries wolf is one people quietly stop trusting, and a suite nobody trusts is worse than not having one.

Cofactor is live now. We're a small group, scattered across a few time zones, and we ship most days. If this sounds like your week, the docs will show you how it works, or you can just email us and tell us what keeps breaking.