Senior Software Engineer, Processing

Headquarters: Remote Lithic is the modern card issuing and processing platform empowering ambitious financial companies to build the future of payments. Our infrastructure powers card programs for 100+ innovative clients, from fintechs reimagining credit and digital banking to platforms transforming disbursements and spend management. Companies like Mercury, Flex, and Novo rely on Lithic's developer-friendly APIs, direct network connections, and flawless reconciliation to launch and scale card programs in weeks, not years. We're building a future where access to better financial products materially improves people's lives, free from the constraints of 30-year-old mainframes and legacy processors. We're proud to be backed by world-class investors who share that vision, including Bessemer Venture Partners, Index Ventures, Spark Capital, Stripes, and Mastercard, along with many others. We're a team of 170+ across 26 states and 7 countries, headquartered in New York City. Position: Senior Software Engineer, Processing Location: Remote We are hiring a Senior Software Engineer for our Processing team to lead Lithic’s next phase of growth. The Processing team builds and maintains the real-time interfaces between Lithic and external payment networks. Every card authorization, clearing message, and settlement file flows through systems this team owns. The team manages both online and batch transaction flows across Mastercard, Visa, and Amex, along with transaction enrichment, disputes processing, and network compliance. The systems we maintain have strict latency and uptime requirements, because they sit on the critical path for every card transaction. The team also manages the physical network peering with card network partners, so infrastructure and networking expertise are important. The team primarily uses Java, Python, and Kotlin on AWS. What you'll do: Ensure high reliability, low latency, and correctness for Lithic's transaction processing interfaces and