Senior Software Engineer, Treasury

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.

We are hiring for our Treasury team Software Engineers at various levels (II and Senior) who are curious and willing to dive deep and understand our technology and domain in order to solve interesting and hard problems. The Treasury team maintains and builds the backend services that manage the flow of funds between Lithic and third parties. This includes our ledger, ACH and wire infrastructure, and associated reconciliation. The systems we maintain have high standards of reliability and correctness. You will become an expert in the card payments space. The Treasury team primarily uses Python for their tech stack.

The Treasury team builds the mission-critical backend services that orchestrate the flow of funds between Lithic and external financial institutions. This includes engineering our core ledger, ACH and wire infrastructure, and high-precision reconciliation systems. As we handle the movement of money, we build our systems to the highest standards of reliability and correctness.

Our team operates with a high degree of autonomy; we have direct control over what we build and the technical direction we take. Prior fintech experience is not required. You will gain deep expertise in the global payments ecosystem while working with a modern, cloud-native stack primarily utilizing AWS (DynamoDB, Kinesis, Lambda, Step Functions, etc.) and Python.

What You'll Do

Own initiatives from planning to launch, keeping stakeholders informed and aligned while maintaining a high bar for quality.

Own your learning of business domains and technical stacks to build a comprehensive mental model of the Treasury ecosystem and how money moves—while the team helps you get there.

Improve system resilience and ensure high reliability and correctness for Lithic’s ledger and orchestrated funds flows.

[Senior] Lead the architectural direction and solve our most complex technical challenges, ensuring our systems scale gracefully as we grow. What You Bring

Business and technical curiosity: You have a natural drive to peel back layers of a system until you understand the root cause of a problem and how it impacts the broader financial ecosystem.

A structured approach to learning: You demonstrate a growth mindset centered on building complete mental models of complex systems.

Autonomy and urgency: You have high agency and thrive in an environment where you are given a problem space rather than a list of tasks, moving with purpose to deliver high-quality solutions.

[Senior] Experience building distributed systems: You have the technical judgment required to design and scale high-stakes infrastructure where reliability and correctness are foundational. The annual US salary range for this role is $160,000 - $200,000 plus equity. This salary range...