I spent 20 minutes trying to log into an app last week.

Good reviews. Slick demo video. The kind of product that makes you think “why didn’t someone build this sooner.” I couldn’t get past the login screen. When I filed a bug report, the response came back: yes, sign in is broken, we’re working on it.

Sign in. The first thing every single user has to do.

It’s easy to laugh at, but I see this as a pattern right now. Teams racing to ship AI features, new integrations, a redesigned dashboard, while the foundations quietly crack. Because the flashy stuff gets the demo, the press mention, the LinkedIn post. Nobody writes about the login flow that just works every time.

But that’s the problem. The fundamentals are invisible when they’re working and catastrophic when they’re not. A house built on a weak foundation doesn’t fail gradually. It holds, and holds, and holds, and then it doesn’t.

Authentication. Performance under load. Reliable notifications. Boring, unglamorous, never makes it into a launch video. But nothing else you build matters if these aren’t solid. The AI copilot, the personalisation engine, the beautiful new onboarding flow – all of it sits on top of whether your product actually works when someone shows up and tries to use it.

The best teams I’ve seen treat the fundamentals as non-negotiable. Not a phase you get through on the way to the interesting work. And unlike features, where good enough is sometimes good enough, the fundamentals don’t get partial credit. Login has to work. Every time. For every user. Ninety-nine percent is not a pass. That’s why the teams who get this right are also obsessive about test coverage on the basics. Not the exciting stuff. The boring critical path that every single user touches, every single day.