Senior Software Engineer - Payments

Location: San Francisco

Department: Engineering

Senior Software Engineer - Payments Platform

At Kikoff, we’re redefining how people build financial confidence, helping millions of Americans establish credit, access smarter financial products, and reach their goals.

Payments power everything we do at Kikoff, and we’re doubling down on building a best-in-class payments platform. As part of a broader product team, you’ll own the systems and integrations that move money reliably and intelligently - powering repayment experiences, enabling seamless payment provider integrations, and driving experiments that improve repayment success rates. These systems will process hundreds of millions of dollars in payments annually, forming the financial backbone of Kikoff’s business.

We’re looking for a Senior Software Engineer who’s excited to tackle complex backend systems and integrations while helping shape the technical foundation of Kikoff’s payments experience. You’ll have significant ownership over how we process payments, manage risk, and create a reliable, customer-first financial platform.

What You’ll Be Doing

• Design and implement core backend systems for payments processing, reconciliation, and transaction management — scaling to handle hundreds of millions of dollars in volume.

• Own the payments domain within Kikoff’s core product team, ensuring reliability, scalability, and high-quality user experiences.

• Integrate with third-party payment providers and internal services, building robust APIs and data pipelines that ensure accuracy and consistency at scale.

• Experiment and iterate on payment and repayment flows to improve conversion and repayment success rates.

• Collaborate cross-functionally with product, data, and finance teams to ensure payments are seamless, compliant, and insightful.

• Contribute across the stack on user-facing experiences tied to core subscription payments and related features — from checkout and repayment flows to account management.

• Extend payments capabilities beyond Kikoff’s own products to support external transaction data, helping users build a holistic picture of their finances.

• Enhance observability and reliability, introducing monitoring, alerting, and fault tolerance into payment-critical systems.

• Support adjacent product areas, contributing to shared systems and features beyond payments as part of a cross-functional engineering team.

What We’re Looking For

• 5+ years of experience building and scaling production systems.

• Experience with Ruby on Rails is a plus but not required; we value strong fundamentals and the ability to learn quickly.

• Deep understanding of system design, API development, and integrations, especially with third-party platforms or payment providers.

• Experience with payment processing systems, ACH, cards, or other financial transaction flows is a major plus.

• Comfort working across the stack and collaborating closely with mobile and product engineers.

• Passion for experimentation and optimization, using data and iteration to improve customer outcomes.

• Strong product sense — you care about building the right thing, not just building it right.

• A builder’s mindset — thrives in ambiguity, takes initiative, and enjoys owning systems end-to-end.