Senior Software Engineer

Mastercard Mastercard · Fintech · O Fallon, MO +1 · Engineering

Senior Software Engineer role at Mastercard focused on building authentication and security solutions for the Identity Solutions platform. Responsibilities include designing, developing, deploying, and maintaining scalable, cloud-native applications and microservices using Java and Spring Boot, with a strong emphasis on performance, scalability, reliability, and security. The role involves translating requirements into designs, leading system design discussions, writing tests, optimizing performance, applying secure coding practices, and troubleshooting production issues. Collaboration with product, security, and platform teams, as well as mentoring junior engineers, is expected. Experience with cloud platforms, containerization, and Agile environments is required.

What you'd actually do

  1. Design, build, test, deploy, and maintain scalable, cloud-native applications and microservices
  2. Develop REST APIs using Java and Spring Boot, focusing on performance, scalability, and reliability
  3. Translate requirements into well-structured designs and architecture, ensuring maintainability and security
  4. Lead and contribute to system design discussions, aligning with architectural standards and best practices
  5. Write and maintain unit, functional, and integration tests to ensure quality and reliability

Skills

Required

  • Experience building RESTful services using Java and Spring Boot
  • Strong experience designing scalable systems using modern software design and architecture principles
  • Experience with cloud platforms (AWS, Azure, or GCP) and containerization (Docker, Kubernetes)
  • Proven ability to work independently on complex technical problems and support team outcomes
  • Experience writing and maintaining unit, functional, and integration tests
  • Strong understanding of performance engineering (analyzing and optimizing systems at scale)
  • Expertise in secure coding practices and vulnerability management
  • Experience leading and contributing to code reviews and engineering standards
  • Strong troubleshooting and root cause analysis skills in complex environments
  • Solid understanding of data structures and their impact on performance and scalability
  • Experience building systems with strong operability, monitoring, and reliability practices
  • Experience working in Agile/Scrum environments and collaborating across teams
  • Strong communication and collaboration skills, with the ability to influence technical decisions
  • Experience mentoring or supporting other engineers
  • Bachelor’s degree or equivalent experience

Nice to have

  • Knowledge of event-driven architectures (Kafka or similar)
  • Experience in high-throughput or regulated environments (payments, banking, fintech)
  • Exposure to AI/automation tools within software development workflows

What the JD emphasized

  • secure coding practices
  • vulnerability remediation
  • high-throughput or regulated environments