senior software developer - back end.

We are seeking an experienced Senior Software Developer - Back End specializing in mainframe enterprise systems to support core system modifications, application modernization, and database integration. In this role, you will analyze logical and physical database structures, author technical specifications, and write PL/I and NetCOBOL code to support online, batch, and workstation interfaces. Working across mainframe and mid-tier architectures, you will develop XML processing transactions, build checkpoint-restartable batch jobs, construct database calls, execute unit/integration testing, and perform defect remediations.

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

Duration: 11-month contract.

Advantages
Specialized Enterprise Mainframe Scope: Lead core backend development on mission-critical z/OS mainframe environments.

Hybrid Mainframe & Modern Integration: Drive advanced integration between mainframe PL/I transactions, XML processing, and mid-tier web services.

Dual Language & Database Exposure: Work across PL/I and NetCOBOL programming alongside both DB2 relational and IMS hierarchical databases.

Dedicated Onsite Collaboration: Work directly alongside senior technical coordinators, DBAs, and systems analysts in a focused 5-day per week workspace.

Responsibilities
System Analysis & Technical Design: Analyze existing logical and physical system designs, code structures, and database architectures to author comprehensive technical specifications in accordance with enterprise QA standards.

Mainframe Application Development: Develop, modify, test, and debug online, batch, and workstation code using PL/I and NetCOBOL within IBM z/OS environments.

Database & Transaction Processing: Design and execute database calls for relational and hierarchical databases (DB2 for z/OS, IMS DB HALDB/DEDB) utilizing PLITDLI APIs.

Mid-Tier & XML Integration: Develop PL/I transactions that process XML input, generate XML output, and integrate mainframe IMS TM applications with mid-tier platforms and non-mainframe web services.

Batch & Screen Engineering: Write checkpoint-restartable IMS Batch Message Processing (BMP) programs, configure Message Format Service (MFS) screen handling, and script secure file transfers (SFTP).

Testing & Defect Remediation: Prepare test environments, generate test data, execute unit and integration testing, analyze defects, and perform code retrofits with cross-functional development teams.

Source Control & Governance: Utilize enterprise source control repositories (Endevor, Harvest) and mainframe diagnostic tools to maintain code libraries, troubleshoot failures, and ensure operational stability.

Qualifications
Mainframe Operating Systems & Utilities: 10+ years of programming and analysis experience with z/OS V2.2 or higher, DFSORT, and mainframe file/database tools (File Aid V10.1+ or IBM File Manager V13.1+) (Strictly Required).

Recent PL/I Programming: Hands-on experience using PL/I V4.5 or higher within the last 5 years (Strictly Required).

Mainframe XML Integration: 5+ years of experience writing mainframe PL/I transactions that process, produce, and consume XML input/output (Strictly Required).

Hierarchical & Relational Databases: Demonstrated experience with IMS DB V12 or higher (HALDB and DEDB) using PLITDLI APIs, as well as DB2 for z/OS V11 or higher (Strictly Required).

Mainframe Tools & Source Control: Experience using IBM Debug Tool V13.1+, failure diagnostics (Abend Aid V12.4+ or IBM Fault Analyzer V13.1+), and Endevor source control (Strictly Required).

Client/Server & Screen Handling: Experience developing Windows client applications interacting with IMS TM, including MFS and SCREENIO screen handling (Strictly Required).

Nice-to-Have Assets:
Hands-on experience with Fujitsu NetCOBOL V4 or higher.

Experience writing checkpoint-restartable IMS BMPs and scripting SFTP transfers in a mainframe environment.

Knowledge of public sector transportation, vehicle licensing, or safety policy frameworks.

Familiarity with Windows workstation tools such as Visual Studio and Harvest Source Control.

Summary
If you're interested in the "Senior Software Developer - Back End" 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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