via Ashby
$100K - 140K a year
Build and maintain resilient backend services and APIs for fraud detection and transaction monitoring in financial systems.
3+ years backend engineering experience with APIs, microservices, distributed systems, cloud infrastructure, preferably in fintech or payments.
About OnePay OnePay is the consumer fintech trusted by millions of Americans to make money better. Our financial system is broken. High fees, low rates, and too few ways to actually grow your money. We’re fixing it. And we’re moving fast. We’re an all-in-one financial services platform that brings together banking, high-yield savings, credit cards, point-of-sale lending, investing, and crypto in one place. We also partner with employers, HCM providers, gig platforms, and others to deliver embedded financial services to millions of employees and frontline workers. We’re backed by Walmart, the world’s largest retailer, and Ribbit Capital, one of fintech’s most respected investors, giving us rare scale, distribution, and the opportunity to build something truly category-defining. But what really sets OnePay apart is how we move. Our customers don’t have time to wait… and neither do we. This place moves fast, and we’re looking for people who are: Ready to run Hungry and driven by urgency Exceptional at what they do, with low ego Comfortable operating in motion The Role As a Software Engineer on the Risk team, your work will directly impact the systems that protect our customers and company. You will: Build resilient backend services that power fraud detection, identity verification, and transaction monitoring at scale. Develop, test, and maintain backend services and APIs that enable real-time risk and fraud prevention. Partner with product managers, and other engineers to design and deploy systems that protect customer accounts and transactions. Implement integrations with third-party risk and compliance platforms, ensuring seamless and secure data flows. Contribute to architectural decisions that balance scale, security, and reliability across sensitive financial systems. Build clear documentation to support collaboration, transparency, and operational excellence. You Bring 3+ years of professional experience in backend engineering, ideally within fintech, payments, or external customer facing systems. Proficiency in building and maintaining APIs, microservices, and distributed systems. Familiarity with cloud infrastructure (AWS, Kubernetes, or similar) and database technologies. Experience working with risk, fraud, or compliance systems is a plus. Drive and proactivity – everyone here is a builder and executor. Tools We Use We use Node and TypeScript on the server, leveraging the NestJS framework within a microservice-oriented architecture running on Kubernetes and AWS. On the client side, we build and ship product features for iOS, Android, and web platforms using React Native. While you don’t need experience with our exact stack, familiarity with modern software engineering practices will help you ramp up quickly. What We Offer Competitive base salary, stock options, and health benefits from Day 1 401(k) plan with company match Remote-friendly (US), flexible time off (FTO), and opportunities for growth A high-growth, mission-driven, inclusive culture where your work has real impact Standard Interview Process Initial Interview with Talent Partner Technical or Hiring Manager Interview Team Interview Executive Interview Offer! Equal Employment Opportunity To build technology and products that are used and loved by people and solve real-world problems, we need to build a team with many different perspectives and experiences. We are an equal opportunity employer. We do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status. We encourage candidates from all backgrounds to apply. Applicants in need of special assistance or accommodation during the interview process or in accessing our website may contact us at talent@onepay.com.
This job posting was last updated on 2/24/2026