When I worked integrating payment gateways I learned to love state machines. They make code easier to maintain. State machines helped me get rid of the chainsa

When I worked integrating payment gateways I learned to love state machines. They make code easier to maintain. State machines helped me get rid of the chainsaw juggling with 10 different boolean flags that was responsible for countless bugs and bad customer experience. It's not over-engineering, it's about keeping things predictable and under control.