Senior Software Engineer

Confidential; San Francisco (CA); On-site; USD 180,000 - 240,000; Full time

Job summary

Confidential in San Francisco is seeking a Senior Software Engineer to join the Platform team. You will design, build, and maintain core infrastructure enabling banking integrations and high‑volume payment processing.

Work with Product, Architecture, and other engineers to ensure secure, reliable systems. You will implement robust APIs, ensure security best practices, and push for architectural improvements while mentoring teammates.

Qualifications

• 5+ years of software engineering, with scalable backend and API experience.
• Commercial payments knowledge or fintech familiarity is preferred.
• Strong Java/Spring and containerization expertise.
• Experience with distributed systems, databases, caching, and messaging queues.
• Security-first approach to data protection, encryption, and secure APIs.
• Familiarity with AI tooling to improve engineering speed and quality.
• Excellent problem-solving and collaborative skills.
• Strong written and verbal communication for cross-functional work.

Responsibilities

• Platform Development: design and implement core platform services and APIs for banking integrations.
• Integration Engineering: build secure, scalable integrations with financial institutions and networks.
• Code Quality: write maintainable, well-tested code and contribute to standards.
• System Reliability: ensure high availability, performance, monitoring, alerting.
• Cross-functional Collaboration: partner with Product, Architecture, QA, and other teams.
• Technical Innovation: improve performance, dev experience, and internal tooling.

Skills

5+ years experience

Backend systems design

APIs and integrations

Security-minded development

Communication

Tools

Java

Spring

Kubernetes

AWS

GCP

Azure

Microservices

Containers

CI/CD

APIs

Job description

About

We are on a mission to revolutionize B2B payments. We’re a well-funded, early-stage startup operating in stealth mode, building cutting-edge solutions that will transform the way businesses move money. If you’re excited about tackling big problems from the ground up, we want to hear from you.

As we grow, we are looking for a Senior Software Engineer to join our Platform team and help build the core infrastructure that powers our payment solutions. You’ll work on challenging technical problems while contributing to the foundation of our technology stack.

About The Role

As a Senior Software Engineer on the Platform team, you will be responsible for designing, building, and maintaining critical systems that enable our integrations with banking partners. You will report to the Engineering Manager and work alongside a talented team of engineers focused on creating scalable, reliable, and secure payment infrastructure. Your work will involve developing robust APIs, implementing secure transaction processing systems, and building the platform that facilitates high-volume financial transactions.

You will collaborate closely with Product, Architecture, and other Engineering teams to ensure our platform solutions align with product requirements and business objectives while maintaining the highest standards of security and reliability.

Key Responsibilities

• Platform Development: Design and implement core platform services, APIs, and infrastructure that support our banking integrations and payment processing systems.
• Integration Engineering: Build and maintain secure, scalable integrations with major financial institutions and payment networks.
• Code Quality & Best Practices: Write clean, maintainable, and well‑tested code while contributing to architectural decisions and technical standards.
• System Reliability: Ensure high availability and performance of platform services, implementing monitoring, alerting, and error handling best practices.
• Cross-functional Collaboration: Work closely with Product, QA, and other Engineering teams to deliver features that meet business requirements and user needs.
• Technical Innovation: Identify opportunities to improve system performance, developer experience, and engineering processes. Drive improvements to internal tooling, contribute to shared infrastructure and company libraries, and help evolve our technical architecture.

Qualifications

• Experience: 5+ years in software engineering, with demonstrated experience building scalable backend systems and APIs and leading projects.
• Commercial Payments Knowledge: Understanding of commercial banking, payments processing, or fintech systems. Experience with financial data handling and compliance requirements preferred.
• Technical Expertise: Strong proficiency in Java, Spring framework, and containerization technologies like Kubernetes. Experience with microservices architecture and cloud platforms (AWS, GCP, or Azure).
• System Design: Experience designing and implementing distributed systems, with knowledge of database design, caching strategies, and message queues.
• Security-First Mindset: Understanding of security best practices, especially in financial services contexts, including data encryption, secure API design, and compliance requirements.
• AI Tooling Proficiency: Strong proficiency with modern AI coding assistants (e.g., Claude Code, GitHub Copilot, or similar) and a proven ability to leverage them to enhance engineering speed, quality, and impact.
• Problem‑Solving Skills: Ability to debug complex issues, optimize performance, and architect solutions for high‑scale systems.
• Communication & Collaboration: Strong written and verbal communication skills, with the ability to work effectively in a fast‑paced, cross‑functional environment.

Preferred Qualifications

• Experience with real‑time payment systems or high‑frequency transaction processing
• Knowledge of banking APIs, SWIFT messaging, or ACH processing
• Experience with event‑driven architectures and stream processing
• Familiarity with enterprise DevOps practices and infrastructure as code

Why Join Us?

• Build Foundational Technology: Work on core platform services that will scale to handle millions of transactions and shape the future of B2B payments.
• Technical Growth: Tackle complex engineering challenges while working with cutting‑edge technologies in the fintech space.
• Collaborate with Excellence: Work alongside experienced engineers from SAP and fintech innovators who value technical craftsmanship.
• Early‑Stage Impact: Your code and architectural decisions will have direct impact on our product and company trajectory.
• Learning & Development: Gain deep expertise in financial technology, distributed systems, and high‑scale platform engineering.

We’re building transformative technology in payments and looking for curious, driven people to join us. Whether or not you meet every qualification, what matters most is your initiative, willingness to grow, and passion for building secure, performant, and user‑friendly web applications.

We embrace AI as a powerful tool for innovation and welcome team members eager to leverage it in their work. As an equal opportunity employer, we’re committed to diversity, inclusion, and creating an environment where everyone can thrive.