MMS/RPG Engineer

CapNexus is hiring a Senior Software Engineer to build and support IBM i applications, DB2 for i data, and business-system integrations. The role owns technical outcomes, architecture and delivery quality, while setting engineering standards and mentoring teammates through an agentic development workflow.

Responsibilities:

• Build and maintain IBM i applications in free-format RPGLE, SQLRPGLE, and CL, using ILE concepts such as procedures, service programs, and modules
• Work with DB2 for i through SQL and DDS, including physical and logical files and subfiles
• Integrate IBM i applications with other systems through web services, JSON and XML, FTP, and the Integrated File System (IFS)
• Support changes through testing, deployment, and post-deployment, and resolve technical issues directly with client teams
• Set coding and testing standards for IBM i work, and identify where modernizing an application pays off
• Own the technical outcome for a system area or major feature set: propose the approach, define the task breakdown, and deliver with minimal escalation
• Design APIs and data models that account for cost, scale, and failure, and build in observability (logging, tracing, and metrics) from the start
• Work with Cloud Engineers on infrastructure as code and CI/CD so what you build deploys the same way every time
• Partner with the Solutions Architect on solution design and with the Engagement Manager on delivery, and turn designs into a build plan the team can execute
• Set code-quality standards for your area, and mentor Software Engineers I and II through pairing and reviews that teach, including how to direct AI tooling and check what it produces
• Join architecture presentations and technical deep-dives alongside the Solutions Architect when the client needs your depth
• Set the tooling approach for a codebase or engagement: which work goes to a conversion engine, which is spec-driven build, where the human-in-the-loop gates belong, and how the toolchain is wired for the problem at hand
• Own the quality of the handoff from specification to build. Make sure specs are executable and actually satisfy the requirements, and hold delivered work to a defined readiness bar. When generated code is wrong, fix the spec, not just the output
• Be the final judgment on correctness for high-risk changes, including in unfamiliar domains, by designing the evidence that proves behavior is preserved
• Design and maintain the project-specific setup of our delivery tooling (steering, agent roles, templates, quality gates, and metrics) as durable capability, not one-off scaffolding

Requirements:

• 5+ years of professional software engineering experience
• A strong grasp of architecture concepts: event-driven and service-based design, API design, data modeling, separation of concerns, and designing for change
• Experience owning a significant system from design through production, and mentoring the engineers who built it with you
• Working knowledge of CI/CD and infrastructure as code
• Hands-on experience with spec-driven or agentic development workflows, where specs drive code generation, for example Kiro, Claude Code, Amazon Q Developer, or Cursor with rules. Using AI only for autocomplete or snippets doesn't count
• A track record of catching what AI-generated or refactored code gets quietly wrong, and of building the tests and gates that prove behavior is preserved
• Hands-on experience programming on IBM i (AS/400, iSeries): free-format RPGLE, SQLRPGLE, CL, and OS/400 commands
• Strong SQL skills on DB2 for i, plus working knowledge of DDS, subfiles, and older RPG (RPG III and fixed format)
• Experience with IBM i Access Client Solutions or iSeries Navigator, the IFS, and JSON and XML
• Experience with Blue Yonder (JDA) MMS
• Experience with AWS or application modernization, such as integrating IBM i applications with AWS services or moving IBM i workloads to modern platforms
• Experience with Java, including Java on IBM i or RPG-to-Java modernization
• Experience supporting IBM i in an enterprise data center
• Background in retail