Most of the work happens before any code is written.
Planning and researchThe hardest part. Once I can picture how a non-technical person will use it daily, the project is nearly done.
InterfaceDesigned for every screen size.
BackendAPIs, tool calling and the first pass of the logic.
TestingEdge cases, then fixes to the interface and flow.
Agents test their own work
Rule files make each AI agent click through the flows and screenshot the interface across screen sizes before I review anything.
Add lines, don't rewrite
When something already works, I have the AI add only the new lines. If it breaks, the cause is easy to find and I can revert.
Duplicates stopped in the database
For anything that costs money or must happen once, like a message or a payout, I set a database rule. A retry then can't send or spend twice.