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# Software Engineer II

- **Company:** Mastercard
- **Location:** O'Fallon, MO, United States
- **Salary:** $92,000.0 - $147,000.0
- **Contract:** Permanent contract
- **Skills:** Java (Programming Language), Application Programming Interfaces (APIs), Agile Methodology, Software Applications, Application Performance Management, Application Release Automation, Software Quality, Code Review, Cyber Security, Information Systems, Continuous Integration, Data Structures, Software Debugging, Software Design Patterns, Distributed Systems, Fraud Prevention and Detection, IntelliJ IDEA, WildFly (JBoss AS), Object-Oriented Software Development, Oracle (Applications), Performance Tuning, Scrum Methodology, Software Architecture, PuTTY, Scaled Agile Framework, Secure Coding, Software Construction, Software Engineering, Software Systems, PL-SQL, Systems Architecture, Testng, Web Applications, Software Organization, Enterprise Software Applications, Test-Driven Development (TDD), Postman, Software Security, Spock, Build Management, Integration Tests, Solid Principles, Information Technology, Toad (Software), Splunk, Jenkins, Microservices
- **Published:** August 26, 2026
- **Apply:** https://www.careerboard.com/us/en/find-jobs-in-United-States/-A2233ABD76EF5AE694/

## About the Role

Strong software development and testing experience, particularly using Java.
Experience designing, developing, testing, and supporting enterprise-scale software applications.
Strong understanding of object-oriented programming, software design principles, and commonly used design patterns.
Experience contributing to software architecture discussions and designing scalable, highly available distributed systems.
Experience developing automated unit, functional, and integration tests.
Knowledge of data structures, algorithms, and performance optimization techniques.
Familiarity with secure coding practices and application security fundamentals.
Experience performing code reviews and promoting software engineering best practices.
Strong troubleshooting and debugging skills with the ability to identify and resolve complex technical issues.
Experience analyzing application performance and optimizing systems for scalability and reliability.
Familiarity with multi-tier web applications and high-performance transaction processing systems.
Experience working with development, testing, and release teams in Agile environments.
Skilled at explaining technical problems clearly and succinctly.
Strong communication, collaboration, and organizational skills.
Self-motivated with a high degree of initiative and ownership.
Ability to learn quickly and work effectively within geographically distributed teams.
Knowledge of Agile software development practices, continuous integration, and test-driven development.
Bachelor's degree in Computer Science, Engineering, Information Systems, Information Technology, or equivalent practical experience., Strong Core Java programming experience
Experience designing and developing enterprise software applications
Experience with Continuous Integration systems (eg, Jenkins)
Oracle, PL/SQL, and advanced SQL scripting
Experience with code reviews and software development best practices
Knowledge of software design principles and object-oriented design
Experience with automated unit, functional, and integration testing
Experience with Testing frameworks such as TestNG and Spock
Knowledge of secure coding practices
Experience with production troubleshooting and root cause analysis
Knowledge of Splunk, including dashboards, alerts, and monitoring
Experience with IDEs such as IntelliJ IDEA or JBoss Developer Studio
________________________________________
Preferred Skills
Experience with distributed systems at scale
Experience contributing to software architecture and scalability initiatives
Knowledge of performance engineering and application optimization
Experience designing observable and operationally resilient systems
Experience using tools such as Postman, PuTTY, WinSCP, and Toad
Experience working within cloud-native or microservices-based environments 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 (see below) 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.

## Description

Successfully deliver as part of a team on major projects and complex assignments with broad scope and long-term business implications.
Design, develop, test, and maintain high-quality software solutions using Java and related technologies.
Contribute to software design and system architecture discussions to build scalable, resilient, and high-performing applications.
Build and enhance features, services, and APIs that support Mastercard's fraud prevention and payment processing platforms.
Develop and maintain automated unit, functional, and integration tests as part of the software development lifecycle.
Participate in code reviews to ensure software quality, maintainability, security, and adherence to engineering standards.
Collaborate with software engineers, quality engineers, product teams, and platform teams to deliver solutions efficiently.
Apply secure coding practices and engineering best practices throughout the development lifecycle.
Contribute to performance engineering efforts by identifying bottlenecks and implementing scalable solutions.
Design and build systems with strong operability, observability, monitoring, and reliability characteristics.
Assist with production support by troubleshooting complex issues, identifying root causes, and implementing sustainable solutions.
Continuously improve development, testing, deployment, and release automation processes.
Be an integral part of Agile SAFe discovery, elaboration, sprint planning, and delivery activities.
Communicate, collaborate, and work effectively in a global environment., All activities involving access to Mastercard assets, information, and networks comes with an inherent risk to the organization and therefore, it is expected that every person working for, or on behalf of, Mastercard is responsible for information security and must:

 * Abide by Mastercard's security policies and practices;
 * Ensure the confidentiality and integrity of the information being accessed;
 * Report any suspected information security violation or breach, and
 * Complete all periodic mandatory security trainings in accordance with Mastercard's guidelines.


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