Stripe

Stripe was founded in 2010 by the Irish brothers Patrick and John Collison and has dual headquarters in South San Francisco and Dublin. It set out to let a developer accept a payment with a few lines of code.

Its payments API grew into a financial infrastructure platform: Billing for subscriptions, Connect for marketplaces, Radar against fraud, Terminal for in-person payments, Issuing for cards, and stablecoin payments through Bridge.

Stripe is known for its documentation and developer experience. Much of it runs on Ruby, and it open-sourced the Sorbet type checker and the Markdoc documentation framework.