Principal Software Engineer, Payments

Live Nation Entertainment, through its Ticketmaster NA division, operates large-scale live event ticketing and payment systems. The Principal Software Engineer will maintain and modernize high-throughput C++ payment processing platforms, migrate legacy systems, build gateway and gRPC integrations, strengthen security and compliance, and support reliable production payment operations.

Responsibilities:

• 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

Requirements:

• 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
• Approaches legacy systems with respect and curiosity, recognizing the constraints and decisions that shaped them
• Takes time to understand existing systems before proposing improvements or modernization
• Continuously improves code and systems incrementally while maintaining stability
• Balances modernization efforts with the realities of production environments that require high reliability
• Demonstrates a strong security-first mindset, especially in systems handling sensitive transactions
• Understands the critical nature of payment processing and the need for accuracy, resilience, and uptime
• Navigates complex systems with care, ensuring minimal disruption while driving improvements
• Shows enthusiasm for evolving legacy systems into modern, scalable solution
• Systems thinker who can reason across layers — from compiler optimization to cache behavior to network latency to business impact
• Strategic modernizer who understands incremental improvement over wholesale rewrite and can articulate when to pay down technical debt versus when to live with it
• Security-conscious developer who treats buffer safety, memory safety, and integer correctness as default concerns, not afterthoughts
• Pragmatic problem solver who can work within the constraints of legacy systems while steadily steering them forward
• Growth-oriented engineer who starts in maintenance but is motivated to grow into systems design, gRPC service architecture, and broader payments ecosystem work
• Collaborative communicator who explains reasoning clearly, asks good clarifying questions, and engages as a peer — can disagree constructively and change their mind when presented with new information
• Detail-oriented professional who understands the operational stakes of financial transaction processing
• Systems thinker able to reason across layers—from low-level performance (compiler optimization, cache behavior, network latency) to overall business impact
• Strategic modernizer who prioritizes incremental improvements and can balance technical debt decisions pragmatically
• Security-conscious developer who treats memory safety, buffer handling, and data integrity as foundational principles
• Pragmatic problem solver who works effectively within legacy system constraints while steadily driving improvements
• Growth-oriented engineer motivated to evolve from maintenance work into system design, service architecture, and broader ecosystem ownership
• Collaborative communicator who articulates reasoning clearly, asks thoughtful questions, and engages constructively with peers
• Open-minded professional who can challenge ideas respectfully and adapt perspective based on new information
• Detail-oriented with a strong understanding of the operational and financial impact of transaction processing systems