REST vs. GraphQL vs. Async: The Best API Strategy for 2025

APIs are the backbone of fintech, but not all models serve the same purpose. REST offers simplicity and stability, GraphQL provides flexibility for complex data needs, and Async delivers real-time responsiveness. This article breaks down the strengths, weaknesses, and use cases of each, drawing on real-world examples from Stripe, Netflix, and PayPal. The takeaway: winning fintech systems don’t choose one approach—they blend REST, GraphQL, and Async into hybrid architectures that balance stability, scale, and speed.