This position is listed on behalf of a partner company, which manages all applications and next steps. Our partner is looking for a Full-Stack Engineer (Backend Leaning) – Payments Engineering based in United States. As a Full-Stack Engineer specializing in backend development, you will help build and evolve the payment infrastructure that powers a rapidly growing AI technology platform. You will work on critical systems responsible for billing, usage tracking, pricing, and payment processing across self-service and enterprise customers. Your work will directly impact revenue accuracy, customer experience, and the reliability of financial operations. You will contribute to modernizing existing systems, developing scalable event-processing services, and integrating new payment solutions while ensuring seamless migrations. Working closely with Engineering, Product, Growth, Finance, Tax, and Sales teams, you will solve complex technical challenges in a fast-paced, AI-first environment. This remote opportunity offers significant technical ownership, opportunities to tackle challenging engineering problems, and the freedom to make a measurable impact on products used by millions of people and businesses worldwide.