Lead Software Engineer, Fullstack

DAVE VS. GOLIATH. WE’RE DAVE.
Lumen Dynamics is a financial app on a mission to build products that level the financial playing field. It is redefining the financial landscape by leveraging technology to create an affordable, transparent, and user-centric access to liquidity for millions of Americans. As a leading innovator in the U.S. financial services sector, Lumen Dynamics’s digital financial platform offers products designed to meet the credit needs of those underserved by traditional financial institutions. Lumen Dynamics’s offerings include its flagship ExtraCash product, providing members up to $500 within minutes. The company is on track to launch several new product offerings in 2026, including a Buy Now Pay Later (BNPL) option.
Lumen Dynamics is focused on serving Americans who are financially vulnerable or living paycheck to paycheck. Lumen Dynamics is leading the charge in creating a new era of credit products that prioritizes speed, affordability, and accessibility, making it the go-to financial partner for those who need it most.
The Opportunity
Lumen Dynamics is looking for a talented Lead Fullstack Engineer to continue building products that help millions of people improve their relationship with money. If you're excited to join a tight-knit collaborative team with a mission of helping others, we'd love to hear from you!
This squad is building a major zero-to-one product with the potential to become a $100M+ revenue line within the next three years. The team is tackling one of the largest recurring financial burdens our members face, giving them more flexibility and control over when and how they pay. It's an early-stage, high-impact opportunity to shape the architecture, culture, and direction of a product from the ground up.
We’re looking for someone who thrives on solving hard problems, is passionate about finding innovative solutions not just for today but allowing for growth of the future, delights customers, and inspires colleagues.
What You'll Build and Own
– Provide technical leadership and assist guiding the team's overall technical direction.
– Write clean, maintainable, and scalable code following best practices (e.g., modular architecture, state management, performance optimization).
– Lead design and work breakdown sessions
– Implement requirements in TypeScript
– Lead and mentor other engineers in contributing to projects on our roadmap, including but not limited to, Implement dashboards and alerts for system faults and participate in on-call rotations
– Lead and evangelize best practices through code reviews, pair programming, presentations at engineering group meetings, rich documentation,
– You will be contributing mainly to the architecture and coding in the backend, but need to be able to assist our engineers in the frontend and build systems which take into considerations the needs and requirements of a customer facing application
– Champion code quality and testability
– Participate in 24/7 on-call rotations

Experience Required
– 6+ years of experience in software development
– 2+ years of technical leadership experience
– Ability to make sense of abstract initiatives and break work down into digestible work packages in order to distribute work among teammates
– Basic understanding of algorithm design paradigms, data structures, asymptotic analysis
– Ability to write provable code in various types of imperative and declarative programming languages and the ability to make trade-off decisions
– Understanding of mocking, unit testing, code coverage, and integration testing
– Experience working with distributed architectures
– Experience with TypeScript or JavaScript
– Experience with CI/CD pipelines for mobile applications (including mobile app build processes leveraging Fastlane)
– Proficiency in working with third-party SDK integrations
– Strong debugging and problem-solving skills
– Excellent communication and teamwork abilities
Bonus
– Good understanding of mobile UI/UX principles and design patterns
– Knowledge of GraphQL
– Experience with automated mobile testing frameworks and test-driven development
– Experience building libraries, tools, and services for other software engineers instead of end users
– Knowledge of performance optimization techniques for mobile applications
Technologies We Use
– React + React Native
– GraphQL
– TypeScript (Node.js)
– Github Actions
Don’t let imposter syndrome get in the way of an incredible opportunity. We’re looking for people who can help us achieve our mission and vision, not just check off the boxes. If you’re excited about this role, we encourage you to apply. You may just be the right candidate for this or other roles.
Why you’ll love working here:
At Lumen Dynamics, our people are just as important as our product. Our culture reflects the values that guide who we are, how we work, and what we aspire to be. Lumen Dynamicss are member-centric, helpful, transparent, persistent, and better together. We striv