senior software developer.

We are seeking a highly accomplished Senior Software Developer with master-level expertise in multi-tier enterprise systems and open-standard technologies to lead full-stack development, systems analysis, and application integration initiatives. In this role, you will take technical ownership of translating complex business requirements into scalable, robust backend services and interactive user interfaces. Operating across hybrid environments that merge legacy mainframes with modern cloud-adjacent architectures, you will direct solution designs, manage deployment pipelines, and provide strategic technical leadership to ensure absolute performance and platform alignment.

Location: Toronto, ON (Fully Onsite – 5 days/week required)

Hours: 7.25 hours per day between 8:00 AM and 5:00 PM

Duration: 12-month contract.

Advantages
Expansive Technical Domain Scope: Master a highly diverse technology ecosystem that spans core legacy mainframe systems, open-source Java environments, and contemporary REST/JSON endpoints.

Architectural Blueprint Authority: Command absolute design and modeling ownership, driving the creation of conceptual, logical, and physical blueprints from inception to release.

High-Impact Technical Mentorship: Step into a prominent technical leadership role, guiding the development practices, quality gates, and code standards of a multidisciplinary IT project delivery team.

Predictable, Highly Collaborative Cadence: Benefit from a structured, fully onsite 12-month engagement optimized for face-to-face synergy, rapid project gating reviews, and immediate operational impact.

Responsibilities
Full-Stack Enterprise Engineering: Lead the end-to-end analysis, design, coding, and system integration of complex multi-tier applications across web, desktop, mobile, and legacy mainframe computing platforms.

Multi-Tier Solution Design: Architect, build, and optimize backend integration layers using JEE, EJB, JNDI, JDBC, JMS, and the Struts Framework alongside server engines like WebSphere, WebLogic, Tomcat, and Apache.

API Architecture & Messaging: Design and deploy decoupled, secure RESTful and SOAP/WSDL-based Web Services, managing high-volume enterprise transactions utilizing JSON and XML messaging schemas.

Database Programming & Optimization: Design relational data layers and write highly optimized PL/SQL programmable logic, stored procedures, and triggers inside Oracle RDBMS environments.

Technical Project Leadership: Provide expert technical oversight and mentorship to system analysts, developers, and testers—overseeing work estimation, task allocations, and the delivery of end-to-end enterprise IT solutions.

Blueprint Modeling & Artifact Creation: Author detailed technical documentation, user guides, and Software Architecture Deliverables covering conceptual, logical, and physical system states using CASE tools such as MS Visio and PowerDesigner.

Identity & Access Security: Implement secure interaction boundaries, managing integrations with enterprise identity grids, cryptographic structures, and network controls (LDAP, PKI, and VPN).

Tier-3 Troubleshooting & Bug Isolation: Act as a principal triage authority to identify, analyze, and resolve deep-seated technical incidents, software bottlenecks, and systemic failures via deep-dive debugging, code refactoring, and performance optimization.

Quality Verification & Testing Lifecycle: Develop rigorous unit and integration testing scripts, collaborating tightly with QA automation squads to build validation paths for system functionality, stress testing, and vulnerability auditing.

Governance & Gating Compliance: Navigate applications smoothly through corporate technology checkpoints, ensuring reference designs strictly meet enterprise security, user privacy, and digital accessibility directives.

Knowledge Transfer & Handover: Formulate clear knowledge-transfer checklists and lead technical walkthrough sessions to transition codebases cleanly to internal operational staff.

Qualifications
Enterprise Systems Engineering Seniority: 10+ years of progressive professional experience designing, architecting, and developing complex IT solutions within multi-platform enterprise landscapes (Strictly Required).

Master-Level JEE Ecosystem Depth: Extensive hands-on experience programming with multi-tiered, open-standard technologies: JSP/Servlets, JEE, EJB, JNDI, JDBC, JMS, and the Struts Framework (Strictly Required).

Decoupled API & Service Engineering: Expert-level command of building, testing, and documenting REST and SOAP-based Web Services utilizing JSON/XML parsing, Swagger, or Postman (Strictly Required).

Database Modeling & Tuning Prowess: Proven professional experience executing relational database analysis, logical mapping, and PL/SQL development within Oracle RDBMS architectures (Strictly Required).

Infrastructure Middleware Fluency: Demonstrated background configuring, monitoring, and maintaining enterprise web servers, explicitly WebSphere, WebLogic, Tomcat, Apache, and Sun Solaris or Windows Server hosts (Strictly Required).

Systems Triage, Debugging & Refactoring: 10+ years of proven expertise isolating multi-component software errors, rewriting complex legacy modules, and running performance optimization tracks (Strictly Required).

Software Modeling Tool Stack Mastery: Strong technical background developing architectural blueprints using CASE platforms like MS Visio or PowerDesigner, alongside active IDE usage (IntelliJ, Eclipse, or VS Code).

Identity Governance & Security Competency: Practical understanding of cryptographic systems and enterprise authentication protocols, specifically PKI, LDAP, and VPN layers.

Soft Skills: Superior analytical problem-solving, consultation, and communication mechanics, with an established history of presenting complex technical solutions to both IT engineering teams and non-technical business executives.

Nice to Have:
Prior professional software development experience navigating formal architecture checkpoints, gating review methodologies, or ITIL frameworks within a Canadian public sector or ministry cluster.

Summary
If you're interested in the "Senior Software Developer" role based in Toronto, we encourage you to apply online at Only qualified candidates will be contacted for the next steps. We look forward to hearing from you!

Randstad Canada is committed to fostering a workforce reflective of all peoples of Canada. 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 to ensure their ability to fully participate in the interview process.

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