In 2019, as a new engineer at Stripe, I built a feature for our team’s top user. We added tests, rolled it out successfully, and our user was happy.

I also set myself up for disaster.

Two years later, some other team discovered a data anomaly, and it blew up into a huge incident involving multiple state regulators and took six months to clean up.

My mistake turned out to be really simple.

I’d updated our main system, one that powered the API and user-visible aspects of this feature. Some other team, millions of lines of code away, owned a different system that processed transaction data. I was supposed to have updated that system too. However, I didn’t know I was supposed to do that — no one on my team knew — so I didn’t, and two years later … 💥

This example plays out everywhere. Once you have more than a couple of people, codebases become a primordial soup: dozens, hundreds, thousands of components; interacting in millions of combinations; much of it glued together with tribal knowledge and neglected documentation.

But that documentation lives apart from your code. And there’s too much of it for you to read and remember everything.

*Someone* knew that when I made my change in the main system, I should’ve also updated that other system. Maybe someone even documented it. But that knowledge never made it to me.

More documentation isn’t the answer. What you really want is just-in-time feedback: something that tells you about the unknown unknowns; something that stops you when you’re about to set yourself up for disaster … maybe something that can automatically fix things for you.

That’s what we’re building at Tanagram: something that takes your documentation, existing PR comments, discussions in Slack, and other sources of tribal knowledge, and makes them clearly visible and enforceable.

Tanagram can use AI to detect patterns, find the relevant information, and do things on your behalf in response to code changes — if you want it to. You can bring your own API keys, or plug into a self-hosted open-source model if you’d like. Or you can turn off the AI functionality, and continue to use Tanagram’s compiler-precise understanding of your codebase.