Senior Software Engineer, Card Authorization

<p> <strong>Headquarters:</strong> Remote </p> <div class="content-intro"><p>Lithic is the modern card issuing and processing platform empowering ambitious financial companies to build the future of payments.</p> <p>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.</p> <p>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.&nbsp;</p> <p>We're a team of 170+ across 26 states and 7 countries, headquartered in New York City.&nbsp;</p></div><p>We are hiring a <strong>Senior Software Engineer</strong> for Lithic’s Card Authorization team, which owns the real-time systems that make every card authorization decision correct, reliable, and fast. The team also owns related fraud tooling, including Lithic’s Rules Engine and 3D Secure integration. You’ll own high-impact projects end-to-end, solve distributed-systems problems at scale, and help build the tools customers use to control fraud and payment risk.</p> <h3><strong>What you'll do:</strong></h3> <ul> <li>Write reliable, secure, scalable code for Lithic’s real-time authorization and fraud-prevention systems with minimal tech debt</li> <li>Build customer-facing features, such as rules improvements, velocity controls, 3DS flows, fraud tooling, and transaction monitoring. Own projects from planning to launch.</li> <li>Improve the reliability of systems in team’s scope and participate in the team on-call rotation</li> <li>Lead efforts to improve systems and processes within the team</li> </ul> <h3><strong>What you'll bring:</strong></h3> <ul> <li>4+ years building production backend systems. Full stack experience is a plus.</li> <li>Experience in or desire to learn Rust; ability to understand Lithic’s system written in other programming languages (Python, Java)</li> <li>Interest and experience in leveraging AI tools to enhance productivity</li> <li>Ability to navigate ambiguity, align diverse perspectives, and drive toward practical solutions</li> <li>Experience or interest in payments, fintech, fraud prevention.</li> <li>Comfort with designing systems from scratch and owning the product