Stripe

Stripe's API is the gold standard for developer experience. Payment intents, subscriptions, invoicing, and multi-currency support — all with documentation that makes complex financial operations understandable.

The webhook system is reliable. Event-driven payment processing with retry logic, signature verification, and idempotency built in. Stripe handles PCI compliance so you never touch card data directly. The cost per transaction is higher than some alternatives, but the engineering time saved on integration and maintenance more than compensates.