{"schemaVersion":"jobsearcher.job.v1","id":"329f6632492347f6d73e987e","url":"https://jobsearcher.com/jobs/329f6632492347f6d73e987e","canonicalUrl":"https://jobsearcher.com/jobs/329f6632492347f6d73e987e","title":"Senior Java Application Developer (onsite)","description":"Senior Java Application Developer\nWashington, DC - ONSITE\nType: Multi-year Contract\nUS citizenship required per government contract\nMust be able to obtain Public Trust clearance\n\nWe 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.\n\nThe Senior Application Developer will leverage knowledge of Object-Oriented Programming, software development methodologies, and the Java language to seamlessly transition our systems to the desired version. The position requires expertise in technologies such as Servlet, JSP, Tag Library, JavaBean, and SQL Server database, invaluable in ensuring smooth and successful migration.\n\nProficiency in tools like Maven, JavaScript, jQuery, Knockout.js, HTML, and CSS is valuable for modernizing the user interface and enhancing the overall user experience. Incumbent must be well-versed in Windows authentication, SSL, session management, and Single Sign-On (SSO) technologies, familiarity with Spring, Spring MVC, and ORM technologies like Hibernate and JPA - these are instrumental in seamlessly integrating the upgraded systems with our existing infrastructure.\nFamiliarity with RESTful web services, JSON parsing, and multipart/form-data file management is highly valued, as is expertise in vulnerability remediation techniques such as CSRF, SQL injection, XSS, and reflection attacks.\n\nUpgrade experience:\n\nPrevious experience successfully migrating Java applications across multiple major versions\nKnowledge of common pitfalls and solutions when upgrading Java applications\nUnderstanding of deprecated features and their modern replacements\nExperience identifying and resolving compatibility issues\n\nBuild, Deployment and CI/CD:\n\nProficiency with build tools (Maven/Gradle)\nExperience updating build pipelines to accommodate newer Java versions\nDependency management skills and handling library compatibility challenges\nExperience with continuous integration/continuous deployment (CI/CD) pipelines (Azure DevOps, GitLab)\n\nOperations and Maintenance Skills:\n\nExperience with application performance monitoring tools and techniques\nKnowledge of log management and analysis systems\nAbility to create and maintain runbooks for operational procedures\nProficiency in identifying and resolving production issues\nUnderstanding of JVM tuning and garbage collection optimization\nExperience implementing and maintaining automated health checks\nKnowledge of security patch management and vulnerability assessment\n\nAdditional Technical Skills:\n\nVersion control with Git\nFamiliarity with application servers (e.g., Tomcat, WebSphere, WildFly)\nKnowledge of common enterprise integrations (SQL Server databases, messaging systems)\nExperience with containerization technologies (Docker, Kubernetes) is a plus\n\nSoft Skills:\n\nExcellent written and verbal communication skills\nStrong problem-solving abilities and attention to detail\nAbility to document migration processes, decisions, and technical debt\nSelf-motivated with the ability to work independently\nCollaborative approach when working with existing development teams\nStrong time management skills to deliver migration within schedule constraints\nExperience providing on-call support and incident management\n\nSystem One, and its subsidiaries including Joulé, ALTA IT Services, and Mountain Ltd., are leaders in delivering outsourced services and workforce solutions across North America. We help clients get work done more efficiently and economically, without compromising quality. 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.\n\nSystem 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.\n\n#M1\n#LI-VH1\n#DI-VH1\n\nRef: #851-Rockville-S1","company":"Systemone","rawCompany":"systemone","city":"Washington","state":"DC","isRemote":false,"isActive":false,"createdAt":"2026-04-14T10:51:34.962Z","occupations":[{"code":"15-1252.00","title":"Software Developers","slug":"software-developers"},{"code":"15-1254.00","title":"Web Developers","slug":"web-developers"},{"code":"15-1251.00","title":"Computer Programmers","slug":"computer-programmers"}],"industries":[{"code":"541512","title":"Computer Systems Design Services","slug":"computer-systems-design-services"},{"code":"541511","title":"Custom Computer Programming Services","slug":"custom-computer-programming-services"},{"code":"513210","title":"Software Publishers","slug":"software-publishers"}],"jobPosting":{"@context":"https://schema.org","@type":"JobPosting","title":"Senior Java Application Developer (onsite)","description":"Senior Java Application Developer\nWashington, DC - ONSITE\nType: Multi-year Contract\nUS citizenship required per government contract\nMust be able to obtain Public Trust clearance\n\nWe 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.\n\nThe Senior Application Developer will leverage knowledge of Object-Oriented Programming, software development methodologies, and the Java language to seamlessly transition our systems to the desired version. The position requires expertise in technologies such as Servlet, JSP, Tag Library, JavaBean, and SQL Server database, invaluable in ensuring smooth and successful migration.\n\nProficiency in tools like Maven, JavaScript, jQuery, Knockout.js, HTML, and CSS is valuable for modernizing the user interface and enhancing the overall user experience. Incumbent must be well-versed in Windows authentication, SSL, session management, and Single Sign-On (SSO) technologies, familiarity with Spring, Spring MVC, and ORM technologies like Hibernate and JPA - these are instrumental in seamlessly integrating the upgraded systems with our existing infrastructure.\nFamiliarity with RESTful web services, JSON parsing, and multipart/form-data file management is highly valued, as is expertise in vulnerability remediation techniques such as CSRF, SQL injection, XSS, and reflection attacks.\n\nUpgrade experience:\n\nPrevious experience successfully migrating Java applications across multiple major versions\nKnowledge of common pitfalls and solutions when upgrading Java applications\nUnderstanding of deprecated features and their modern replacements\nExperience identifying and resolving compatibility issues\n\nBuild, Deployment and CI/CD:\n\nProficiency with build tools (Maven/Gradle)\nExperience updating build pipelines to accommodate newer Java versions\nDependency management skills and handling library compatibility challenges\nExperience with continuous integration/continuous deployment (CI/CD) pipelines (Azure DevOps, GitLab)\n\nOperations and Maintenance Skills:\n\nExperience with application performance monitoring tools and techniques\nKnowledge of log management and analysis systems\nAbility to create and maintain runbooks for operational procedures\nProficiency in identifying and resolving production issues\nUnderstanding of JVM tuning and garbage collection optimization\nExperience implementing and maintaining automated health checks\nKnowledge of security patch management and vulnerability assessment\n\nAdditional Technical Skills:\n\nVersion control with Git\nFamiliarity with application servers (e.g., Tomcat, WebSphere, WildFly)\nKnowledge of common enterprise integrations (SQL Server databases, messaging systems)\nExperience with containerization technologies (Docker, Kubernetes) is a plus\n\nSoft Skills:\n\nExcellent written and verbal communication skills\nStrong problem-solving abilities and attention to detail\nAbility to document migration processes, decisions, and technical debt\nSelf-motivated with the ability to work independently\nCollaborative approach when working with existing development teams\nStrong time management skills to deliver migration within schedule constraints\nExperience providing on-call support and incident management\n\nSystem One, and its subsidiaries including Joulé, ALTA IT Services, and Mountain Ltd., are leaders in delivering outsourced services and workforce solutions across North America. We help clients get work done more efficiently and economically, without compromising quality. 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.\n\nSystem 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.\n\n#M1\n#LI-VH1\n#DI-VH1\n\nRef: #851-Rockville-S1","datePosted":"2026-04-14T10:51:34.962Z","dateModified":"2026-04-14T10:51:34.962Z","hiringOrganization":{"@type":"Organization","name":"Systemone","sameAs":"https://jobsearcher.com"},"jobLocation":{"@type":"Place","address":{"@type":"PostalAddress","addressLocality":"Washington","addressRegion":"DC","addressCountry":"US"}},"identifier":{"@type":"PropertyValue","name":"JobSearcher","value":"329f6632492347f6d73e987e"},"url":"https://jobsearcher.com/jobs/329f6632492347f6d73e987e"}}