Senior Java Engineer - AS400 & Application Development

We are looking for a senior Java engineer with deep L3 and L4 support experience and extensive hands-on work on the IBM i (AS400) platform. The role combines production support, complex solution development, and architectural input across multiple business applications. You will resolve escalated incidents, drive root cause analysis, enhance existing systems, and contribute to project delivery in a structured ITIL-governed environment.

Key Responsibilities:

• Provide L3 and L4 support for business-critical applications: troubleshoot escalated incidents, perform root cause analysis, and implement permanent fixes.
• Design, develop, and deploy complex Java-based solutions and integrations, including those that interface with IBM i / AS400 systems.
• Contribute to solution design and architecture: review technical designs, recommend patterns, and guide modernization and integration decisions.
• Support and enhance multiple applications concurrently, prioritizing effectively across incidents, problems, changes, and project work.
• Participate actively in projects from requirements and design through build, testing, deployment, and hypercare.
• Manage incidents, problems, changes, and service requests in ServiceNow in line with ITIL processes and SLAs.
• Plan and track work in JIRA (stories, tasks, defects, sprints, boards, dashboards).
• Perform code reviews, enforce coding standards, and mentor junior and mid-level engineers.
• Create and maintain technical documentation, runbooks, knowledge articles, and support handover material.
• Collaborate with business users, QA, DevOps, infrastructure, and vendor teams; communicate status and risks clearly to stakeholders.
• Participate in on-call or shift rotations and major incident bridges as required.

Required Qualifications:

• 15+ years of total IT experience, with strong Java development and support experience.
• Proven L3 and L4 support background: complex defect analysis, code-level fixes, performance tuning, and vendor escalation handling.
• Extensive hands-on experience on the AS400 / IBM i platform.
• Experience writing complex solutions and some level of architecture experience (solution design, integration design, technical leadership).
• Demonstrated ability to support multiple applications at the same time and engage in project work.
• Full understanding of ITIL: incident, problem, change, release, and knowledge management, SLAs, and major incident handling (ITIL v3/v4 certification preferred).
• Hands-on experience with ServiceNow (SNOW) for ITSM and JIRA for work management.
• Excellent analytical, communication, and stakeholder management skills.

Technical Skills

Core Java and frameworks

• Java 8 / 11 / 17+, OOP, multithreading and concurrency, collections, streams, JVM tuning and memory management
• Spring Framework, Spring Boot, Spring MVC, Spring Data, Spring Security, Spring Batch, Spring Cloud
• Hibernate / JPA, MyBatis, JDBC
• Jakarta EE (Servlets, JSP, EJB, JMS), legacy Struts exposure a plus

Web services and integration

• REST and SOAP web services, JSON / XML, Swagger / OpenAPI
• Messaging: JMS, Apache Kafka, ActiveMQ, RabbitMQ, IBM MQ
• Integration patterns, ESB / middleware exposure (Oracle SOA/OSB, MuleSoft, or similar)
• Microservices architecture, API gateway concepts, OAuth2 / JWT

IBM i / AS400

• IBM i (AS400) architecture, DB2 for i, libraries, objects, and job management
• RPG / RPGLE, CL, COBOL awareness; reading and troubleshooting legacy code
• JT400 / JTOpen toolkit, JDBC to DB2 for i, data queues, program calls, and Java-to-RPG integration
• Batch job scheduling, spool file handling, and performance analysis on IBM i
• Modernization approaches: API enablement, service wrapping, and incremental refactoring

Databases

• DB2, Oracle, SQL Server, or PostgreSQL; advanced SQL, stored procedures, query tuning and indexing

Build, DevOps, and quality

• Maven / Gradle, Git, Bitbucket / GitHub / GitLab, Jenkins or equivalent CI/CD
• JUnit, Mockito, integration testing, SonarQube / code quality tools
• Docker; Kubernetes and cloud (AWS / Azure / OCI) exposure a plus
• Application servers and web servers: WebLogic, WebSphere, Tomcat, JBoss, Apache / Nginx

Monitoring and troubleshooting

• Log analysis, thread and heap dump analysis, profiling and performance tuning
• Monitoring and APM tools such as Splunk, ELK, Dynatrace, AppDynamics, or New Relic

Service management and delivery tools

• ServiceNow (incident, problem, change, knowledge, reporting), JIRA, Confluence
• ITIL-aligned processes, SLA and KPI reporting, RCA and problem record documentation

Preferred Qualifications

• ITIL Foundation or higher certification; Oracle or Java certifications
• Experience in retail, publishing, distribution, or ERP-integrated environments
• Exposure to Agile / Scrum and hybrid support-plus-project delivery models
• Experience modernizing or migrating legacy platforms
• Experience working with onshore/offshore delivery teams

Soft Skills

• Strong ownership and accountability for production stability
• Calm and structured under major incident pressure
• Clear written and verbal communication with technical and business audiences
• Ability to mentor and influence without formal authority
• Self-driven, able to context-switch across applications and priorities