Senior Java Software Engineer

Position Title: Senior Software Developer (10+ years) Location: Toronto, ON Mode: Contract Position Overview Client is seeking a highly experienced Senior Software Developer to support the design, development, modernization, and maintenance of large-scale enterprise applications. The successful candidate will work onsite and collaborate closely with business analysts, architects, testers, and stakeholders to deliver secure, reliable, and well-documented software solutions in alignment with OPS standards. Key Responsibilities Conduct requirements analysis in collaboration with business analysts and stakeholders Design and document solution architectures, including conceptual, logical, and physical models Participate in architecture checkpoints and solution design walkthroughs Develop, integrate, and maintain system and solution components Perform application modernization activities, including migration from WebSphere Application Server to Open Liberty/Liberty and upgrading Java applications from Java 8 to Java 9+ Patch WebSphere Application Server and troubleshoot compatibility and performance issues Develop unit and integration test cases and support system, performance, and security testing Prepare and maintain complete technical documentation and user guides Support knowledge transfer activities and walkthroughs for technical team members Collaborate effectively with internal teams, vendors, and service delivery partners Manage multiple assignments concurrently while meeting project deadlines Mandatory Qualifications and Experience Minimum 10 years of demonstrated experience in IT systems development across multi-platform and multi-tier environments Strong experience with enterprise Java technologies, including JSP, Servlets, JSF, JEE, EJB, JNDI, JDBC, JMS, XML, JSON, REST and SOAP-based web services Proven experience migrating applications from WebSphere Application Server (WAS) to Open Liberty or Liberty Demonstrated experience upgrading applications from Java 8 to Java 9 or higher Experience patching and supporting WebSphere Application Server and resolving compatibility issues Strong experience with application servers such as WebSphere, Tomcat, WebLogic, and Open Liberty Experience with Oracle RDBMS (19c or higher) and PL/SQL Experience with development and deployment tools, including GitHub, Jenkins, and DevOps practices Knowledge of cloud technologies, containerization, hosting, deployment, and networking Technical Skills and Competencies Advanced knowledge of full-stack, multi-tier system design and integration Strong experience with REST APIs, SOAP/WSDL services, JSON/XML messaging, and UI technologies Proficiency with development and design tools such as Eclipse, IntelliJ, Visual Studio Code, MS Visio, and Power Designer Strong debugging, refactoring, and performance optimization skills Communication and Interpersonal Skills Excellent written and verbal communication skills Ability to prepare clear technical documentation and explain complex solutions to technical and non-technical audiences Strong consulting, collaboration, and stakeholder engagement skills Proven ability to work independently and as part of a team Demonstrated ability to manage multiple priorities in a fast-paced environment Public Sector Experience (Asset) Familiarity with Ontario Public Service strategies, policies, standards, and guidelines Understanding of OPS IT architecture standards, security, and privacy requirements Previous experience supporting health sector or OPS projects is considered an asset Seniority Level: Mid-Senior level Employment Type: Contract Job Function: Information Technology Industries: IT Services and IT Consulting, Information Services #J-18808-Ljbffr