Lead Software Engineer

Overview

Lead Software Engineer – Mastercard’s Global Credit Authorization team is seeking a Lead Software Engineer (C/C++) to build and enhance high-performance, mission-critical systems that power secure, reliable payment processing at global scale. You will combine software engineering expertise with technical leadership to deliver resilient, scalable solutions while championing software quality across the development lifecycle. You will contribute hands-on development, drive testing strategy, improve system design and testability, and mentor engineers to elevate engineering excellence across the team.

You will work in a collaborative, fast-paced Agile environment where quality, reliability, automation, and continuous improvement are core to how we build software. This is a hybrid position based in O Fallon, MO, requiring three days per week onsite.

• Design, develop, and maintain software solutions using C/C++ for high-performance, scalable systems.
• Develop robust unit tests using Google Test and contribute to automated test frameworks.
• Create comprehensive test plans based on functional requirements and high-level design documentation.
• Execute functional, integration, system, and User Acceptance Testing (UAT) activities.
• Analyze logs, traces, and system behavior to validate functionality and ensure test coverage.
• Perform root cause analysis, identify defects, and drive issues through resolution.
• Champion quality throughout the software development lifecycle and ensure production readiness prior to deployment.
• Identify opportunities for process improvement, automation, and increased engineering efficiency.
• Contribute detailed technical designs, implementation plans, and technical documentation.
• Participate in requirements analysis, backlog refinement, sprint planning, and Agile ceremonies.
• Collaborate closely with engineers, architects, product owners, and cross-functional stakeholders to deliver business outcomes.
• Support production systems through troubleshooting, incident response, and on-call participation.
• Mentor and coach junior engineers, fostering technical growth and engineering excellence.
• Present technical concepts, project updates, and recommendations to both technical and non-technical audiences.
• Promote a culture of collaboration, innovation, continuous learning, and operational excellence.

• Strong software development experience using C/C++ (Java experience is also valued).
• Proven experience developing and executing functional, integration, system, and UAT testing.
• Experience creating test strategies and test plans from high-level technical designs and requirements.
• Deep understanding of software quality practices, test automation, defect management, and test coverage analysis.
• Strong knowledge of Linux/Unix environments and command-line tools.
• Proficiency with scripting languages, preferably Shell scripting.
• Experience using source control systems such as Git in a collaborative development environment.
• Solid understanding of algorithms, data structures, operating systems, and distributed systems concepts.
• Experience developing applications and tests for highly available, performance-sensitive systems.
• Strong familiarity with Agile methodologies, including Scrum, Kanban, CI/CD, and iterative software delivery practices.
• Demonstrated ability to troubleshoot complex technical issues and drive resolutions across teams.
• Excellent analytical, problem-solving, and debugging skills.
• Self-motivated with the ability to manage multiple priorities in a fast-paced environment.
• Strong verbal and written communication skills, with the ability to explain technical concepts clearly to diverse audiences.
• Proven ability to mentor engineers and influence technical direction through leadership and collaboration.
• Bachelor’s degree in Computer Science, Software Engineering, Information Technology, Mathematics, or a related field; equivalent practical experience will also be considered.

• All activities involving access to Mastercard assets, information, and networks come with an inherent risk to the organization and, therefore, it is expected that every person…