Hybrid Senior Software Engineer – Payments

at Kikoff

• Job title: Senior Software Engineer – Payments
• Job type: Full Time
• Experience level: Senior
• Salary: $200,000 - $260,000 per year
• Degree requirement: No Education Requirement
• Tech skills: Ruby, Ruby on Rails
• Location requirements: Hybrid, San Francisco, United States

About the role

• Senior Software Engineer designing backend systems for payment processing in a FinTech unicorn startup. Ensuring reliability and scalability while integrating with third-party payment providers in a hybrid role.

Responsibilities

• 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.

Requirements

• 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.

Benefits

• Medical, dental, and vision coverage - Kikoff covers the full cost of health insurance for the employee!
• Meaningful equity in the form of RSU's
• Flexible vacation policy to help you recharge
• Competitive pay based on experience consisting of base + equity + benefits