Structure.

Discipline fails. Not because people are weak — because discipline is a rate, and rates compound. A team that does the right thing 99% of the time ships the 1% forever.

So I don't trust discipline, mine included. I trust structure. The right structure makes the wrong thing impossible — not discouraged, not linted, not documented in a style guide nobody reads. Impossible. If an app developer can put business logic in the UI shell, someone eventually will, and "someone" includes me at 2am and every AI agent I've ever hired. When that happens I've learned to blame the framework, not the developer. A framework that permits the mistake has already made it.

This is why everything I build has one place where logic lives — a Rust core — and shells that are deliberately too dumb to sin. It's why a bug that requires the app to bend over backwards is, by definition, a bug somewhere lower. And it's why polling makes me irrationally angry: a refresh button is an architectural confession. The world is a stream of events, and a system that keeps asking "anything new?" is structured against the nature of the thing it models. Data should arrive, not be fetched. You don't fix that with guidelines; you fix it by building on a substrate where arrival is the only primitive.

The same logic kills backwards compatibility, at least everywhere I'm allowed to kill it. Every compatibility shim is a payment on a debt you chose not to settle, made by everyone who touches the code after you, forever. "This is wrong, delete it, build it right" has to remain a legal move — the moment it isn't, wrongness becomes load-bearing.

People hear all this as rigidity. It's the opposite. Structure is what buys the freedom: when the system makes correctness inevitable, you stop spending attention on vigilance and spend it on the work.

Discipline is a tax you pay forever. Structure is a tax you pay once.