Software Engineer II

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

Software Engineer II on the Transaction Stream team, responsible for designing, building, testing, and enhancing applications and services that power real-time payment networks at a global scale. Focuses on backend services, APIs, and application features using Java, Spring Boot, and Spring Data JPA, with an emphasis on security, maintainability, and scalability.

What you'd actually do

  1. Design, develop, test, and support software components and services using modern engineering practices.
  2. Build backend services, APIs, and application features that are secure, maintainable, and scalable.
  3. Collaborate within an Agile team to deliver features, participate in code reviews, and support software throughout the development lifecycle.
  4. Troubleshoot issues, identify opportunities for improvement, and help enhance application reliability, performance, and developer efficiency.
  5. Take ownership of assigned work, communicate progress clearly, and continue building technical depth through hands-on delivery and collaboration.

Skills

Required

  • Experience building applications and REST APIs using Java, Spring Boot, and Spring Data JPA.
  • Strong foundation in computer science fundamentals, including data structures, algorithms, and object-oriented design.
  • Ability to write clean, secure, testable code and contribute to unit, service, and integration testing.
  • Comfort working with SQL and relational data concepts.
  • Strong analytical and problem-solving skills, with the ability to debug issues and identify practical solutions.
  • Strong verbal and written communication skills and an ability to work effectively in a collaborative team environment.
  • Self-motivated, organized, and eager to learn, with a passion for continuous improvement and delivering results.

Nice to have

  • Familiarity with front-end development concepts and technologies such as JavaScript or Angular is a plus.