Payment & Billing Systems Engineer

This is a remote position. Our client is looking for a Payment & Billing Systems Engineer to take full ownership of their payment infrastructure and ensure reliability across their subscription-based platform. They operate within the tech and digital product space and have recently scaled their platform capabilities, supporting a growing global user base through subscription-driven services. This role sits at the core of their revenue engine. Payment accuracy, subscription logic, and billing reliability directly impact both user experience and business performance, making this one of the most critical positions on the team. Responsibilities Take full ownership of the payment ecosystem, including Authorize.net as the primary processor and cryptocurrency payment integrations Architect and manage the full subscription lifecycle, including activations, plan changes, cancellations, suspensions, and recovery flows Develop robust webhook handling systems with strong guarantees around idempotency, retries, and event sequencing Build and maintain billing reconciliation processes across multiple intervals, ensuring financial accuracy and traceability Design workflows for refunds, disputes, and chargeback handling Implement automated testing strategies, including integration and end-to-end tests for payment and subscription flows Introduce fraud prevention mechanisms and enforce rate limiting on payment-related endpoints Ensure compliance with payment security standards and best pra