Middle Software Engineer, Credit Card

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 Backend Engineer on the Credit Card team at OnePay, your work will directly shape the infrastructure behind our co-branded credit card product, holding the same bar for trust, security, and reliability as the rest of our financial ecosystem. You will:

• Design and build backend services that power our co-branded credit card product and its integrations with partner systems

• Architect APIs and event-driven systems that handle sensitive financial data securely at scale

• Partner with risk, compliance, and platform teams to ensure new features meet regulatory and security requirements

• Own reliability and performance for systems processing real-time credit transactions

• Drive technical decisions on system design, balancing scalability, security, and speed of delivery

• Mentor other engineers and raise the bar on code quality, testing, and operational practices across the team

You Bring

• 3+ years of professional experience in backend or distributed systems development

• Experience building and operating production-grade APIs and microservices in a regulated or high-compliance environment (fintech, payments, banking, or similar)

• Proficiency in Node.js or similar modern backend frameworks (TypeScript, NestJS, Go, or Java)

• Familiarity with cloud-native architecture (Kubernetes, AWS) and event-driven or microservice-based systems

• Strong understanding of data security, PCI compliance, or similar standards protecting sensitive financial data

• Strong communication and collaboration skills across product, risk, and platform teams

• 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. We also embrace AI-assisted development, so engineers have their choice of Claude Code or Cursor to fit their workflow. 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

Our process varies by role. Most candidates go through:

• AI-assisted initial screen

• Interview with Talent Partner

• Technical or Hiring Manager Interview

• Team Interview

• Executive Interview

• Offer!

Equal Employment Opportunity