Software Development Engineer in Test (SDET) II

MastercardO'fallon, MO
Hybrid

About The Position

Mastercard’s Global Credit Card Authorization team is seeking a Software Development Engineer in Test (SDET) II to help ensure the quality, resilience, and performance of one of the most critical transaction processing platforms in the world. This platform facilitates billions of transactions annually between issuers, acquirers, and service providers across the globe. In this role, you will apply your software development expertise to design and execute robust testing strategies for complex, high‑throughput systems. You will play a key role in raising engineering standards, strengthening production readiness, and embedding quality throughout the development lifecycle.

Requirements

  • Experience as a Software Development Engineer in Test (SDET), Quality Assurance or Quality Engineer with previous experience developing and executing functional, integration, and UAT test strategies for complex systems.
  • Ability to create detailed test plans from high‑level designs and requirements.
  • Strong understanding of software quality practices, defect management, and test coverage methodologies.
  • Hands‑on experience working in Linux environments.
  • Experience with scripting languages, preferably shell scripting.
  • Proficiency in C/C++ or Java for test development and system validation.
  • Experience working in a team environment using source control tools, preferably Git.
  • Strong analytical, critical‑thinking, and attention‑to‑detail skills.
  • Excellent verbal and written communication skills, with the ability to articulate complex ideas clearly and concisely to both technical and non-technical stakeholders.
  • Bachelor degree in Computer Science, Software Engineering, Information Technology, Mathematics, or a related field. Equivalent practical experience may also be considered.
  • Must be eligible to work in the United States, now as well as in the future, without employer sponsorship.

Responsibilities

  • Develop comprehensive test plans based on high‑level design and technical documentation.
  • Design, implement, and execute functional, integration, and User Acceptance Testing (UAT) test cases.
  • Validate system behavior by analyzing application traces, logs, and metrics to ensure complete test coverage.
  • Perform root cause analysis to identify, document, and track software defects.
  • Partner with developers and engineers to remove testing blockers and ensure timely completion of test cycles.
  • Ensure production readiness by proactively identifying and resolving defects prior to release deployments.
  • Contribute to continuous improvement of test processes, tools, and quality practices.
  • Actively participate in agile ceremonies, including story refinement and sprint planning.
  • Collaborate effectively with cross‑functional teams in a fast‑paced, distributed environment.

Benefits

  • insurance (including medical, prescription drug, dental, vision, disability, life insurance)
  • flexible spending account and health savings account
  • 16 weeks of new parent leave
  • up to 20 days of bereavement leave
  • 80 hours of Paid Sick and Safe Time
  • 25 days of vacation time
  • 5 personal days
  • 10 annual paid U.S. observed holidays
  • 401k with a best-in-class company match
  • deferred compensation for eligible roles
  • fitness reimbursement or on-site fitness facilities
  • eligibility for tuition reimbursement
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