Legacy code. We’ve all dealt with it, we’ve all screamed at it. And we’ve all written it. A project becomes legacy when developers no longer have the context of old decisions. The transition to legacy status happens step by step, decision by decision.

Your customers have money, and you’d like them to give it to you. Payment gateways, such as Stripe, Braintree, and Paypal, make it easy to start charging credit cards and get the money flowing. But charging cards is only the beginning. Learn from some of my mistakes and build a robust financial application.