How many layers does your code have?

Even with clean architecture, you only have 4 fundamental layers. And once you have v1, you’re mostly doing tweaking and copy pasting. Any huge refactoring is the business switching its main strategy.

Take an OS like OpenBSD. It has three main layers. The syscall layer, the kernel layer, and the machine dependent code. But an OS is more spread horizontally with various subsystems (process and memory, io and other device, ipc,…)

If you’ve captured your problem’s domain and adopted a pragmatic architecture, you will rarely have to change across all layers. That’s costly and happens mostly due to business reasons.