Job Title: C++ Developer

Location: Remote (USA/Canada) Work Type: Contract

Job Description

We're seeking an experienced C++ engineer to join our Platform Payments team, working on Client's mission-critical payment processing systems. These systems process millions of transactions monthly across multiple payment methods and 20+ gateway providers, powering real-time payments for culture-defining live events at massive global scale. You'll work across a mature C/C++ codebase spanning three decades — from pre-standard patterns in our core authorization gateway to C++17 in our Bazel monorepo. The immediate work is maintenance and strategic modernization of these systems, but this role is explicitly designed to grow: from legacy renovation into systems design, gRPC service architecture, and new technology adoption including Rust. If you're energized by the challenge of understanding why a system was built the way it was before deciding what it should become, this is the role. This is not a maintenance job with a maintenance ceiling. You'll work on systems that power how fans pay for live events worldwide — at a scale where a misconfiguration can cause thousands of payment failures during a major onsale. The intellectual challenge is real: strategic modernization of systems spanning three decades of C++, with a clear trajectory into new technology. There is tremendous green-field work ahead: decomposing legacy IPC into gRPC services, strengthening real-time fraud defenses during peak onsales, optimizing seamless global checkout, integrating new payment methods, and expanding embedded finance that shapes not just ticket purchases but the full in-venue experience. A strong engineer in this role will meaningfully shape the direction of these critical systems.

WHAT YOU WILL BE DOING

Maintain and strategically modernize high-throughput payment processing systems handling real financial transactions in real time Drive platform migration work, including migrating a core Windows C++ authorization gateway to Linux via Clang and Bazel Develop robust payment integrations with third-party gateways (Chase Paymentech, Barclays, HSBC, AMEX, Adyen, Braintree, Klarna, Shift4, and others) Decompose legacy IPC frameworks into gRPC services, enabling payment components to be reused across the broader payments ecosystem — this is the bridge from maintenance into systems design Implement security-critical features involving encryption, PCI compliance, and sensitive payment data handling Optimize performance of transaction processing pipelines where latency directly affects whether a customer completes a purchase Incrementally steer legacy codebases toward modern C++ practices (RAII, ownership semantics, safe string handling) without breaking the payment flows that depend on them 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 takes 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 WHAT YOU NEED TO KNOW (or TECHNICAL SKILLS) 7+ years of professional C++ development experience in production environments Modern C++ fluency Strong understanding of systems programming, including memory management, concurrency, and performance optimization Ability to reason about undefined behavior, and its practical consequences across platforms Systematic debugging methodology Toolchain understanding and cross-compilation concerns Proficiency with build systems — Bazel experience highly valued; Experience working with legacy codebases older than 10 years — ability to understand, respect, and incrementally modernize existing systems Experience with or strong interest in payment processing or financial transaction systems Deep knowledge of security best practices Proficiency with AI-assisted development tools (e.g., Claude, Codex) with mature judgment — uses AI as an accelerator that requires human verification, especially in codebases with undefined behavior where AI-generated code can appear correct and still be wrong Understanding of HTTP/HTTPS protocols and RESTful API design Experience with Linux/Unix environments Rust experience or genuine interest in learning it gRPC experience or familiarity with service decomposition from monolithic architectures Payment gateway integration experience (Chase Paymentech, Braintree, Adyen, or similar) PCI-DSS compliance knowledge and implementation experience Experience with platform migrations (e.g., Windows to Linux, MSVC to Clang) Bazel build system expertise Performance profiling experience Experience with shared memory, IPC frameworks, or low-level concurrency primitives Kafka or other event streaming platforms experience OpenSSL/cryptographic libraries hands-on experience Familiarity with AI-powered code review and static analysis tools Awareness of security considerations when using AI tools with legacy or under-documented systems