Mainframe Developer - IBM

Position Description:

We are seeking a seasoned Mainframe Developer to play a critical role in our enterprise database migration from mainframe systems to the AWS Cloud. In this role, you will investigate, analyze, and modify core legacy mainframe modules to create message queues, enabling seamless data redirection to the cloud via Enterprise Service Bus (ESB) services and modern APIs.
While your primary expertise lies in deep mainframe development (COBOL, CICS, PL/I, DB2, JCL), you will collaborate closely with integration teams using IBM App Connect Enterprise (IBM ACE) to transform our tightly coupled legacy architecture into a modern, event-driven, cloud-ready ecosystem.
Implementation Project Context
The initial assignment involves a large, multi-year enterprise implementation focused on modernizing how core business and customer data is exchanged and governed across systems and digital channels. The program is replacing tightly coupled legacy integrations with a modern, API-first and event-driven architecture, delivering a set of enterprise-grade REST APIs, cloud-based integration services, and asynchronous messaging capabilities that form the backbone of the platform. This includes implementation patterns leveraging publish/subscribe messaging, event-driven architecture (EDA), and change data capture (CDC) to support near real-time propagation of customer and business data changes across enterprise systems.
To facilitate this data redirection without disrupting core operations, the developer will investigate and modify mainframe batch modules and online environments to output to message queues. These queues will be consumed by ESB services and APIs to ensure near real-time, resilient, and secure data propagation to AWS. The integration patterns, messaging contracts, and refactored mainframe components you deliver will form the backbone of this migration and serve as blueprints for future transformation initiatives.

Your future duties and responsibilities:

. Mainframe Investigation & Refactoring: Analyze existing mainframe modules (COBOL, PL/I, CICS, DB2, Batch) to understand data flows and dependencies.
. Queue Integration: Modify and enhance legacy batch modules and online transactions to create and push data into message queues (IBM MQ) for cloud redirection.
. JCL & Batch Optimization: Update and maintain JCL and batch processing flows to support the new migration architecture.
. Integration Collaboration: Partner with integration engineers to map mainframe data structures to ESB services (IBM ACE) and REST APIs.
. Testing & Validation: Ensure the reliability, fault tolerance, and performance of modified mainframe modules to avoid any disruption to day-to-day business operations.
. Build and integrate publish/subscribe and asynchronous messaging solutions

Required qualifications to be successful in this role:

Mandatory Technical Experience (Mainframe)

. Core Mainframe Technologies: Extensive experience with COBOL, PL/I, and CICS.
. Database & Batch Processing: Strong proficiency in DB2 and writing/modifying Batch modules and JCL.
. Messaging Infrastructure: Proven experience working with IBM MQ or similar mainframe messaging queuing systems to facilitate data movement.

Highly Desirable / Excellent-to-Have

. ESB Services: Experience with IBM App Connect Enterprise (ACE) or building message flows for data transformation and routing between disparate systems.
. Cloud & Modern Integration: Familiarity with AWS services (e.g., Lambda, API Gateway, SQS/SNS) and REST API concepts.
. Architecture Patterns: Exposure to Event-Driven Architecture (EDA), Publish/Subscribe messaging, and Change Data Capture (CDC).
. Data Migration Support: Assist in implementing Change Data Capture (CDC) or asynchronous messaging patterns to ensure data consistency between the mainframe and AWS during the coexistence phase.

General Background

. Undergraduate degree in Computer Science, Information Technology, or equivalent practical experience.
. 5+ years of software engineering experience, with a heavy focus on Mainframe systems and data integration.

#LI-ST3

CGI is providing a reasonable estimate of the pay range for this role. The determination of this range includes various factors including but not limited to skill set level, geographic market, experience and training, and licenses and certifications. Compensation decisions are dependent on the facts and circumstances of each case. A reasonable estimate of the current range is $70, - $,.

Skills:

• Amazon Web Services Cloud
• Application Development
• CICS
• COBOL
• Data Migration
• DB2
• IBM Appl. Connect Enterp.(ACE)
• Legacy System Integration
• Mainframe
• PL/I
• RESTful (Rest-APIs)
• Web Components