Back End Developer - Mainframe

Toronto, ON
On-site
Posted Oct 16, 2026
1 position

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Employment type: Contract
Experience level: Lead · 10+ years
Posting language: English
Working hours: 40 hours per week
Seniority: Mid-Senior level
Application method: Direct apply is available

Job summary

Analyze, design, develop, test, and maintain mainframe applications, including PL/I transactions that process XML and integrate with web services and mid-tier systems. Coordinate database and technical design work with cross-functional teams, follow OPS standards, provide project updates, and transfer knowledge to staff.

Job details

The client is seeking a Senior Software Developer Back End (Mainframe) to support the analysis, design, development, testing, and maintenance of mainframe applications within the Labour and Transportation Cluster. The successful candidate will have extensive experience in PL/I programming, IMS databases, DB2 for z/OS, mainframe application development, and client/server integration. Experience supporting driver licensing, vehicle registration, and transportation safety systems within a public-sector environment is highly desirable. Key Responsibilities Analyze existing systems, including logical and physical designs, application architecture, and code structures. Assess technical database requirements and identify necessary changes to support new system functionality. Collaborate with DBAs and data management teams to coordinate database modifications. Prepare technical specifications in accordance with Ontario Public Service (OPS) standards. Participate in Joint Application Development (JAD) sessions, technical walkthroughs, and design sign-off activities. Develop new code and modify existing online, batch, and workstation applications. Develop and maintain mainframe PL/I transactions that process XML input and output and integrate with non-mainframe web services. Support mainframe-to-mid-tier integration using IMS Connect. Collaborate with mid-tier developers, business analysts, QA teams, and other technical stakeholders. Use ministry-mandated source control and code management tools. Provide regular project status updates to the Project Manager and/or Lead Technical Coordinator. Follow OPS technical standards, policies, and procedures. Facilitate knowledge transfer to RUS and I&IT Cluster staff throughout the assignment. Must-Have Skills Recent hands-on experience with PL/I V4.5 or higher within the last 5 years. 5+ years of experience developing mainframe PL/I transactions that process XML input/output and integrate with non-mainframe web services. Experience with IBM z/OS V2.2 or higher. Strong experience with IMS DB V12+, including HALDB and DEDB, using the PLITDLI API. Experience with DB2 for z/OS V11 or higher. Expertise in File-AID V10.1+ or IBM File Manager V13.1+. Nice-to-Have Skills 10+ years of programming and systems analysis experience. Experience with Fujitsu NetCOBOL V4 or higher. Experience designing Windows client applications that interact with IMS TM applications. Hands-on experience with IBM Debug Tool, Abend-AID or IBM Fault Analyzer, and DFSORT. Experience with Endevor and Harvest source control tools. Experience developing checkpoint-restartable IMS BMPs. Knowledge of mainframe screen handling (MFS) and SCREENIO. Experience with Visual Studio 2008+ and Visual Studio Debugger. Knowledge of Ontario driver licensing, vehicle registration, and transportation safety systems. Previous experience working within Ontario Public Service or other public-sector environments.

What you’ll do

Requirements

Requires recent hands-on PL/I experience, at least five years developing XML-processing PL/I transactions integrated with non-mainframe web services, and experience with z/OS, IMS DB, DB2 for z/OS, and File-AID or IBM File Manager. Ten or more years of programming and systems analysis experience and familiarity with transportation systems and public-sector environments are desirable.