Software Engineer II

Software Engineer II

Mastercard’s Global Credit Authorization team is seeking a Software Engineer II (C/C++) who is passionate about building high-performance, mission-critical systems that operate at global scale.

In this role, you will collaborate with talented engineers to design, develop, test, and support innovative solutions that drive Mastercard’s authorization platform. You'll work in a fast-paced, Agile environment where quality, reliability, and continuous improvement are fundamental to our success.

This is a hybrid position based in O'Fallon, MO, with an expectation of three days per week onsite.

• Design, develop, and maintain high-quality, scalable C/C++ software that meets Mastercard’s engineering and security standards.
• Deliver user stories within Agile sprint timelines while maintaining a strong focus on quality and reliability.
• Create comprehensive unit tests and automated test coverage to validate functional and non-functional requirements.
• Partner closely with quality engineers to support functional, integration, and system testing efforts.
• Participate in code reviews and technical design discussions to promote maintainable, efficient, and secure solutions.
• Contribute detailed technical designs and implementation plans for assigned work.
• Actively engage in requirements analysis, backlog refinement, and sprint planning activities.
• Collaborate with engineers, architects, product owners, and other stakeholders to achieve project goals and address technical challenges.
• Take ownership of assigned features and support production systems through incident response and on-call participation.
• Develop and maintain technical documentation that supports operational excellence and long-term maintainability.
• Support continuous improvement initiatives, engineering best practices, and automation efforts across the team.
• Contribute to a collaborative and inclusive team culture focused on learning, innovation, and operational excellence.

• Strong programming experience with C/C++.
• Experience with scripting languages, preferably Shell scripting.
• Experience writing automated unit tests using frameworks such as Google Test or JUnit.
• Experience developing applications on Linux operating systems.
• Experience using source control systems such as Git or Bitbucket in a collaborative development environment.
• Strong understanding of algorithms, data structures, and distributed systems concepts.
• Experience working within Agile methodologies such as Scrum or Kanban, including continuous integration and iterative software delivery.
• Strong analytical and problem‑solving skills with a passion for building reliable, high-performance software.
• Self‑motivated, proactive, and able to manage competing priorities in a collaborative, fast‑paced environment.
• Excellent verbal and written communication skills with the ability to communicate technical concepts to both technical and non‑technical audiences.
• Bachelor’s degree in Computer Science, Software Engineering, Information Technology, Mathematics, or a related field. Equivalent practical experience will also be considered.

This role is not eligible for Mastercard’s work authorization sponsorship. As such, candidates must be eligible to work in the United States, now as well as in the future, without employer sponsorship.

Mastercard is a merit‑based, inclusive, equal opportunity employer that considers applicants without regard to gender, gender identity, sexual orientation, race, ethnicity, disabled or veteran status, or any other characteristic protected by law. We hire the most qualified candidate for the role. In the US or Canada, if you require accommodations or assistance to complete the online application process or during the recruitment process, please contact reasonable and identify the type of accommodation or assistance you are requesting.

Do not include any medical or health information in this email. The Reasonable Accommodations team will respond to your email promptly.

• Abide by Mastercard’s security policies and practices.
• Ensure the confidentiality and integrity of…