Senior Software Engineer

Confidential; San Francisco (CA); On-site; USD 130,000 - 170,000; Full time

Benefits offered by this job

Technical growth opportunities

Collaborative environment

Impact on product trajectory

Job summary

Confidential is seeking a Senior Software Engineer to join our stealth mode startup in San Francisco. This role focuses on building and maintaining the core systems that support our payment solutions, requiring experience in scalable backend development and APIs.

As part of a talented engineering team, you will implement secure transaction processing systems, collaborate cross-functionally, and tackle complex challenges while contributing directly to B2B payment innovation.

Qualifications

• 5+ years in software engineering with backend systems experience.
• Strong skills in Java and Spring framework.
• Familiar with security best practices in financial services.

Responsibilities

• Design and implement core platform services and APIs.
• Maintain secure integrations with financial institutions.
• Drive improvements to internal tooling and architectures.

Skills

Backend systems and APIs

Problem-Solving Skills

Java

Kubernetes

Collaboration

Tools

Spring framework

AWS

GCP

Azure

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.

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 implementation of 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.