Platform Engineer, Core Services

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 an Platform Engineer at OnePay, you will build the core platform services and developer frameworks that power large-scale, distributed systems and enable the next generation of intelligent, agent-driven applications.

What You’ll Do

• Design and operate platform-oriented core services that support high-scale distributed systems across OnePay’s product ecosystem

• Architect, build, and manage Kafka-based event streaming systems that power real-time data flows and mission-critical financial workflows

• Develop internal developer tooling and shared infrastructure that improve velocity, reliability, and observability across engineering teams

• Build and evolve frameworks that support the construction and orchestration of agentic applications, enabling intelligent, automated workflows across products

• Partner closely with engineering, data, and AI teams to solve complex distributed computing challenges in a secure, cloud-native AWS environment

You Bring

• 7+ years of experience in software engineering within fintech, cloud infrastructure, or large-scale distributed systems environments

• Strong hands-on experience designing, operating, and scaling Kafka-based event-driven architectures

• Deep expertise in distributed systems, asynchronous processing, and high-availability platform services

• Production experience in AWS cloud environments and building cloud-native infrastructure

• Experience building developer platforms, internal tooling, or frameworks that enable other engineers to move faster

• Drive and proactivity - everyone here is a builder and executor

Tools We Use

We use Typescript front to back, with node and NestJS frameworks for server code and React Native for our iOS, Android, and Web clients. We run on a highly distributed cloud-native stack with Kubernetes and AWS, and scale and resiliency are at the heart of everything we build. We also embrace agentic development, so engineers have their choice of a variety of models and agent harnesses, including Claude Code, Cursor, Codex, and more 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

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 [email protected].