Principal Software Engineer

Job Description

Engage in maintaining and strategically modernizing high-throughput payment processing systems that handle real financial transactions in real-time. Drive platform migration work, which includes migrating a core Windows C++ authorization gateway to Linux via Clang and Bazel. Develop robust payment integrations with third-party gateways like Chase Paymentech, Barclays, HSBC, AMEX, Adyen, Braintree, Klarna, and Shift4. Decompose legacy IPC frameworks into gRPC services, allowing payment components to be reused across the broader payments ecosystem. Implement security-critical features involving encryption, PCI compliance, and sensitive payment data handling. Optimize the performance of transaction processing pipelines where latency directly affects customer purchases. Incrementally steer legacy codebases toward modern C++ practices without breaking the existing payment flows. Design and implement comprehensive testing, including unit tests, integration tests, and fuzz testing for security-critical components. Debug and resolve production issues in systems with complex interdependencies and real operational stakes. Collaborate with payment operations teams to onboard new payment methods and gateway providers. Ensure compliance with PCI-DSS and other financial industry standards. Participate in on-call rotation for production payment system support.

Qualifications

1. Possess 7+ years of professional C++ development experience in production environments. 2. Exhibit modern C++ fluency. 3. Demonstrate a strong understanding of systems programming, including memory management, concurrency, and performance optimization. 4. Exhibit the ability to reason about undefined behavior and its practical consequences across platforms. 5. Demonstrate systematic debugging methodology. 6. Understand toolchains and cross-compilation concerns. 7. Have proficiency with build systems, Bazel experience is highly valued. 8. Have experience working with legacy codebases older than 10 years and be able to understand, respect, and incrementally modernize existing systems. 9. Have experience with or strong interest in payment processing or financial transaction systems. 10. Have deep knowledge of security best practices. 11. Have proficiency with AI-assisted development tools (e.g., Claude, Codex) with mature judgment. 12. Understand HTTP/HTTPS protocols and RESTful API design. 13. Have experience with Linux/Unix environments. 14. Have Rust experience or genuine interest in learning it. 15. Have gRPC experience or familiarity with service decomposition from monolithic architectures. 16. Have payment gateway integration experience (Chase Paymentech, Braintree, Adyen, or similar). 17. Have PCI-DSS compliance knowledge and implementation experience. 18. Have experience with platform migrations (e.g., Windows to Linux, MSVC to Clang). 19. Have Bazel build system expertise. 20. Have performance profiling experience. 21. Have experience with shared memory, IPC frameworks, or low-level concurrency primitives. 22. Have Kafka or other event streaming platforms experience. 23. Have OpenSSL/cryptographic libraries hands-on experience. 24. Have familiarity with AI-powered code review and static analysis tools. 25. Be aware of security considerations when using AI tools with legacy or under-documented systems.

Benefits

- Medical, vision, dental, and mental health benefits for you and your family. - Access to a healthcare concierge. - Flexible or Health Savings Accounts (FSA or HSA). - Free concert tickets. - Generous paid time off including paid holidays, sick time, and personal days. - 401(k) program with company match. - Stock reimbursement program. - New parent programs including caregiver leave. - Fertility, adoption, foster, or surrogacy support. - Career and skill development programs with School of Live. - Tuition reimbursement. - Student loan repayment. - Volunteer time off. - Crowdfunding match.