The last twenty percent
AI tools get a product to eighty percent in a weekend. Here is what is actually left, and why it takes longer than the first eighty.
- 2 Sep 2026
A founder can now describe an app and have something running the same afternoon. The screens look right, the demo works, and the temptation is to think the project is nearly done. It is not. What has been built is the part that was easy to describe.
What remains is the part that is hard to describe. Who is allowed to read which row. What happens when the payment webhook arrives twice. Where the API keys live. What the app does on a slow connection. What you will look at when a customer says it is broken. None of that shows up in a demo, and none of it is optional once real users arrive.
The order matters too. Security and data integrity come before features, because a permissions bug discovered after launch is a disclosure rather than a ticket. We start every rescue with an audit for exactly this reason. You cannot price the remaining work until you know which of it is load bearing.