Senior AS400 Developer

About Dunnes Stores

Dunnes Stores is Ireland's foremost retailer, leading in food and fashion with over 130 locations across Ireland, Northern Ireland, and Spain, alongside an expanding online platform. The company continues to grow its product and service range to meet dynamic customer demands.

Role Overview

We seek a seasoned Senior AS400 Developer to become part of our technology team in Dublin. The ideal candidate will have extensive experience with IBM i / AS400 platforms, particularly in complex, mission-critical settings, to support, develop, and enhance core business systems essential for daily operations.

Key Responsibilities

• Design, develop, maintain, and upgrade applications running on the IBM i / AS400 environment.
• Engage throughout the software development lifecycle, including requirements analysis, design, development, testing, deployment, and ongoing support.
• Support existing RPG-based applications integral to essential business processes and enhance their functionality.
• Identify and resolve production system issues swiftly by liaising directly with end-users and delivering reliable fixes with controlled deployment.
• Develop and uphold integration solutions connecting AS400 systems with other business applications.
• Collaborate with business and technical stakeholders to convert requirements into effective technical implementations.
• Improve code quality, enhance system performance, augment documentation, and increase supportability across platforms.
• Participate actively in Agile methodologies, including sprint and Kanban workflows, to manage development efforts.
• Provide expert technical guidance for AS400 development initiatives.

Desired Qualifications and Experience

• Proven senior-level proficiency in IBM i / AS400 development environments.
• In-depth hands-on experience with RPG/FREE, RPGLE, and RPG III, with familiarity with ILE RPG preferred.
• Comprehensive knowledge of DB2 database, Command Language (CL), and SQL.
• Practical experience using Data Description Specifications (DDS) and Access Client Solutions (ACS).
• Demonstrated ability in supporting and evolving legacy applications within active business contexts.
• Strong grasp of integration technologies such as web services (SOAP/REST), HTTP, XML, JSON, sockets, and APIs connecting IBM i systems to external platforms.
• Experience with software deployment, release procedures, and change management practices.
• Excellent troubleshooting aptitude and experience in providing production system support.
• Ability to work autonomously with strong ownership of technical deliverables.
• Effective communication skills to interact with both technical teams and non-technical stakeholders, explaining complex technical issues clearly.

Additional Advantages

• Familiarity with development and version control tools like OMS, Turnover, ARCAD, ADM, SVN, or Git.
• Experience with adjacent technologies such as Java, Linux, or Windows environments.
• Previous work exposure within retail, FMCG, wholesale, supply chain, or other high-volume transaction domains.
• Experience supporting systems related to ordering, stock management, receiving, point of sale (PoS), warehousing, handheld devices, or reporting.
• Knowledge of Agile delivery frameworks, including SCRUM, Kanban, and use of Jira.
• Capability to manage both planned release cycles alongside urgent issue resolution and critical changes.

Success Indicators

• Develop a profound understanding of the existing AS400 infrastructure and its critical role in business operations.
• Provide reliable, expert-level development and support services across vital applications.
• Enhance system maintainability, robustness, and integration potential on an ongoing basis.
• Be recognized as a dependable technical expert who adeptly manages complexity within a live operational setting.

Why Join Dunnes Stores?

This role offers the opportunity to engage with pivotal systems fundamental to daily business functions. Working within an established yet evolving environment, you will contribute significantly to enhancing and sustaining critical platforms with meaningful, practical impact.

Dunnes Stores is committed to equal opportunity employment.