Staff Backend Engineer- Product

About OnePay OnePay is a consumer financial services app with an exceedingly simple mission: to help people achieve financial progress. Tens of millions of Americans today are unbanked or underbanked, meaning they don't have enough money in savings to cover a minor emergency. They pay too much in fees, don't have access to credit at affordable rates, and have little ability to grow their wealth. OnePay's vision is to create a single app for consumers to save, spend, borrow, and grow their money, bringing our mission to life with simple and accessible banking, credit, and payments products that deliver a best-in-class experience to millions of customers. Our products include:

• Checking and high-yield savings accounts
• Domestic and international peer-to-peer payments
• Credit Builder and credit score monitoring
• Digital wallet / contactless payment solutions
• Credit card program
• Buy-now-pay-later installment loans at Walmart
• Prepaid mobile service

Why do we have a right to win? We have the backing of Walmart (a Fortune 1) and Ribbit Capital (a preeminent fintech investor), are deeply embedded with the distribution of the world's largest omnichannel retailer, and have an industry-leading multi-product value proposition - all in addition to having some of the best people and talent in the industry. There's never been a better time to build a category-defining business and there has rarely been a team better positioned for the opportunity. Join us! The Role As a Staff Engineer at OnePay, you'll serve as a highly versatile technical leader and contributor, tackling complex engineering challenges across multiple domains. Rather than being tied to a single product or team, you'll be deployed as a utility player where the business needs you most-whether that's scaling systems, guiding architectural decisions, or accelerating delivery of user-facing features. You'll collaborate broadly with engineering, product, and design, and play a pivotal role in shaping OnePay's technical foundation and customer experience.

What You'll Do

• Lead design and implementation of high-scale systems and features across product lines, serving as a trusted technical partner for multiple teams.
• Provide architectural guidance and hands-on contributions to ensure reliability, security, and performance across OnePay's platform.
• Tackle complex, novel engineering problems in areas such as payments, servicing, and consumer-facing experiences.
• Mentor and level up other engineers, raising the technical bar across the org.
• Contribute to shaping the core infrastructure and developer experience that power our products

You Bring

• 10+ years of professional software engineering experience, including at least 3 years in a senior or staff-level capacity driving technical outcomes.
• Proven success building and scaling user-facing products or backend systems in fast-paced environments.
• Proven ability to quickly ramp up across different technical areas and lead complex initiatives, regardless of stack or domain.
• Strong ability to operate autonomously, navigate ambiguity, and quickly align stakeholders.
• Bonus: Experience working with AI-powered or user-facing AI products (e.g., personalization, conversational agents, recommendation systems).
• Drive and proactivity - everyone here is a builder and executor.

Tools we use We use the fp-ts library for functional programming with Node/TypeScript running on top of Kubernetes and AWS. We believe great engineers can learn any stack, so you do not need experience with these specific tools, but you'll ramp up more quickly if you are familiar with functional programming concepts.

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 [email protected]. Apply tot his job Apply To this Job