Software engineer senior H/F (IT)

We are looking for a highly experienced Senior Full Stack Software Developer to support and maintain large-scale, complex legacy applications. This role is focused on the end-to-end lifecycle of mission-critical systems—from impact analysis and technical design to implementation and deployment. You will be responsible for mitigating vulnerabilities, upgrading end-of-life components, and ensuring that changes to the user interface, middleware, and database models are executed with precision and security.

Duration: 12-month contract (Potential for extension)

Project Stability: Long-term 12-month contract with a strong potential for extension.

• Hands-on experience with both modern (React, Microservices, Cloud) and legacy (WebSphere, EJB, Oracle) technologies.
• End-to-End Ownership: Lead the full development lifecycle from initial impact analysis to final production promotion.

Analysis & Design

• Conduct deep-dive impact analysis for business and technical changes, including patching, version upgrades, and security mitigations.
• User Interface, Middleware, Database models, and reporting components.
• Design and validate system component changes for the UI, database schema, and security protocols (authentication/authorization).
• Identify and document comprehensive test cases and update technical documentation in DevOps repositories.

Implementation & Development

• Develop and unit test changes for UI components, middleware, and metadata using JAVA, Spring Boot, and EJB.
• Implement database changes, including indexes, stored procedures, functions, and transaction management.
• Testing & Release Management
• Create scripts for test environment data population and support integrated and user acceptance testing (UAT).
• Promote solutions to test and production environments and analyze server log files to resolve post-deployment issues.
• Package solutions for deployment and document Release Change Lists.
• Ensure all code meets AODA accessibility standards and project quality assurance targets.

Create and maintain operational reports using Power BI.

• Must Have: 10+ years of experience supporting large, complex legacy applications using JAVA, WebSphere, Tomcat, MySQL, and Oracle.
• 7+ years of experience with Oracle DB, PL/SQL, Stored Procedures, and Data Modeling.
• Modern Technical Skills
• 4+ years of experience with Docker, Kubernetes, Microservices, REST APIs, and React/Redux.
• 3+ years of experience with DevOps (GitHub, automated pipelines) and AODA coding standards.
• 5+ years of experience with Power BI for operational reporting.

Knowledge of Client Health-related projects and IT project approval processes (Gating/Unified Methodology).

• Strong experience in Agile/Scrum SDLC methodologies.
• Bachelor’s degree in Computer Science or a related technical field.

If you're interested in the Senior Software Developer - Full Stack role based in Toronto, we encourage you to apply online at

As a result, we are committed to developing and implementing strategies to increase the equity, diversity and inclusion within the workplace by examining our internal policies, practices, and systems throughout the entire lifecycle of our workforce, including its recruitment, retention and advancement for all employees. In addition to our deep commitment to respecting human rights, we are dedicated to positive actions to affect change to ensure everyone has full participation in the workforce free from any barriers, systemic or otherwise, especially equity-seeking groups who are usually underrepresented in Canada's workforce, including those who identify as women or non-binary/gender non-conforming; Indigenous or Aboriginal Peoples; persons with disabilities (visible or invisible) and; members of visible minorities, racialized groups and the LGBTQ2+ community.

Randstad Canada is committed to creating and maintaining an inclusive and accessible workplace for all its candidates and employees by supporting their accessibility and accommodation needs throughout the employment lifecycle. We ask that all job applications please identify any accommodation requirements by sending an email to View email address on randstad.com.