Senior Full-Stack Software Engineer, Unsecured Cards

About the role Halcyon Labs's Cards team is hiring a Senior Full-Stack Engineer to help build and scale our newest card products. You'll work across the stack to ship member-facing experiences and the backend systems that power them — solving complex problems in a fast-moving space and partnering closely with product, design, risk, credit, and compliance to deliver products members trust with their financial lives. These efforts introduce new product constructs and require evolving core systems while delivering seamless, reliable experiences at scale. You'll help define solutions amid ambiguity and ship features that support millions of Halcyon Labs members. The base salary offered for this role and level of experience will begin at $164,000.00 and up to $227,000.00. Full-time employees are also eligible for a bonus, competitive equity package, and benefits. The actual base salary offered may be higher, depending on your location, skills, qualifications, and experience. In this role, you can expect to Own and drive end-to-end development of complex product features, from shaping technical approach through implementation and launch Lead multi-engineer efforts within the team, helping break down problems, define scope, and drive execution Design and build scalable systems across backend services and frontend applications (web and mobile) supporting millions of members Work through ambiguity to define solutions, structuring problems and aligning technical decisions with product and business goals Collaborate closely with cross-functional partners — product, design, risk, credit, legal, and compliance — to deliver high-impact features Contribute to technical design decisions, balancing tradeoffs across performance, reliability, and long-term maintainability Raise the bar for engineering quality through thoughtful code reviews, testing practices, and improving team standards Mentor and support other engineers, helping improve team velocity, code quality, and overall execution Engineers are required to participate in on-call rotation. Being on call may include responding to incidents outside of regular working hours when necessary. To thrive in this role, you have 5+ years of experience building production-grade software, with a track record of shipping reliable, user-facing features Experience owning projects or major features end-to-end, including design, implementation, and delivery Strong backend development experience building APIs and services with Ruby on Rails or comparable frameworks, with working knowledge of modern frontend frameworks (e.g., React, React Native) Experience with transactional databases and caching systems, and an appreciation for clean, well-tested, maintainable code Comfort operating in ambiguous, fast-moving environments, where you help define solutions rather than just implement them Strong collaboration skills, with experience working closely with product managers, designers, and other engineers A mindset focused on impact, quality, and continuous improvement Experience in fintech, lending, or other regulated/credit domains is a strong plus #LI-Onsite #LI-AA1 A little about us At Halcyon Labs, we believe that everyone can achieve financial progress. We created Halcyon Labs—a financial technology company, not a bank*—on the premise that core banking services should be helpful, easy, and free. Through our user-friendly tools and intuitive platforms, we empower our members to take control of their finances and work towards their goals. Whether it's starting a savings account, purchasing a first car or home, launching a business, or pursuing higher education, we're proud to have helped millions unlock their financial potential. We're a team of problem solvers, dreamers, and builders with one shared obsession: our members. From day one, Halcyon Labsrs have worked tirelessly to out-hustle and out-execute competitors to bring our mission to life. Their grit and determination inspire us to work harder every day to deliver the very best experience possible. We each bring an owner's mindset to our work, refusing to be outdone and holding ourselves accountable to meet and exceed the highest bars for our teams, our company, and our members. We believe in being bold, dreaming big, and taking risks, while also working together, embracing our diverse perspectives, and giving each other honest feedback. Our culture remains deeply entrepreneurial, encouraging every Halcyon Labsr to see themselves as stewards of our mission to help everyday Americans unlock their financial progress. We know that to achieve our mission, we must earn and keep people's trust—so we hold ourselves to the highest standards of integrity in everything we do. These aren't just words on a wall—our values are embedded in every aspect of our business, serving as a north star that guides us as we work to help millions achieve their financial potential. Because if we don't—who will? *Halcyon Labs is a financial technology company, not a bank. Banking services provided by The Ban