Senior Java Application Developer; onsite

Overview

Senior Java Application Developer

Location:

Washington, DC – onsite
Type:
Multi-year Contract
US citizenship required per government contract
Must be able to obtain Public Trust clearance

We seek a Senior Application Developer with Java experience and a strong aptitude in modernizing systems. The incumbent will support up to 3 legacy mission-essential systems in the upgrade from Java/JDK 8 to Java/JDK 21 technology and beyond with operations and maintenance.

• Leverage knowledge of Object-Oriented Programming, software development methodologies, and the Java language to migrate systems to newer versions.
• Apply expertise in technologies such as Servlet, JSP, Tag Library, Java Bean, and SQL Server database to ensure smooth and successful migration.
• Modernize the user interface using tools such as Maven, JavaScript, jQuery, Knockout.js, HTML, and CSS.
• Ensure secure integration with existing infrastructure using Windows authentication, SSL, session management, and Single Sign-On (SSO).
• Familiarity with Spring, Spring MVC, and ORM technologies like Hibernate and JPA.
• Familiarity with RESTful web services, JSON parsing, and multipart/form-data file management.
• Apply expertise in vulnerability remediation techniques (CSRF, SQL injection, XSS, reflection attacks).

• Previous experience successfully migrating Java applications across multiple major versions
• Knowledge of common pitfalls and solutions when upgrading Java applications
• Understanding of deprecated features and their modern replacements
• Experience identifying and resolving compatibility issues

• Proficiency with build tools (Maven/Gradle)
• Experience updating build pipelines to accommodate newer Java versions
• Dependency management skills and handling library compatibility challenges
• Experience with continuous integration/continuous deployment (CI/CD) pipelines (Azure Dev Ops, Git Lab)

• Experience with application performance monitoring tools and techniques
• Knowledge of log management and analysis systems
• Ability to create and maintain runbooks for operational procedures
• Proficiency in identifying and resolving production issues
• Understanding of JVM tuning and garbage collection optimization
• Experience implementing and maintaining automated health checks
• Knowledge of security patch management and vulnerability assessment

• Version control with Git
• Familiarity with application servers (e.g., Tomcat, Web Sphere, Wild Fly)
• Knowledge of common enterprise integrations (SQL Server databases, messaging systems)
• Experience with containerization technologies (Docker, Kubernetes) is a plus

• Excellent written and verbal communication skills
• Strong problem-solving abilities and attention to detail
• Ability to document migration processes, decisions, and technical debt
• Self-motivated with the ability to work independently
• Collaborative approach when working with existing development teams
• Strong time management skills to deliver migration within schedule constraints
• Experience providing on-call support and incident management

System One, and its subsidiaries including Joulé, ALTA IT Services, and Mountain Ltd., are leaders in delivering outsourced services and workforce solutions across North America. System One not only serves as a valued partner for our clients, but we offer eligible employees health and welfare benefits coverage options including medical, dental, vision, spending accounts, life insurance, voluntary plans, as well as participation in a 401(k) plan.

System One is an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex (including pregnancy, childbirth, or related medical conditions), sexual orientation, gender identity, age, national origin, disability, family care or medical leave status, genetic information, veteran status, marital status, or any other characteristic protected by applicable federal, state, or local law.