Freelance IBM ACE Developer – Enterprise Integration & API Development

Employment Type: Part-Time Contract
Work Mode: Remote
Experience: 5+ Years (recommended; prioritize hands-on IBM ACE experience)
Industry: IT Services and IT Consulting
Job Description
We are looking for an experienced IBM App Connect Enterprise (ACE) Developer for a part-time, remote contract opportunity. The ideal candidate will have strong hands-on expertise in enterprise integration, ESQL development, IBM MQ messaging, API integrations, and database connectivity.
Key Responsibilities
Design, develop, test, and maintain integration message flows using IBM ACE 13.0.x.
Develop ESQL modules for message transformation, validation, routing, and data enrichment.
Implement IBM MQ messaging patterns, including asynchronous messaging, request/reply, and message correlation.
Configure and troubleshoot ACE nodes, including MQInput, MQOutput, Compute, Filter, Mapping, HTTPInput, HTTPRequest, HTTPReply, TryCatch, and Throw.
Process XML and JSON messages using XMLNSC, namespaces, and XSD validation; support DFDL and MRM-based integrations.
Develop and consume REST APIs and SOAP web services, including OpenAPI 3.x specifications and IBM API Connect integration.
Integrate ACE flows with Oracle, IBM DB2, and Microsoft SQL Server databases.
Develop SQL queries, stored procedures, functions, cursors, result sets, and database-driven data enrichment logic.
Implement exception handling, logging, retries, failure routing, and integration troubleshooting.
Support Jenkins CI/CD pipelines, Git version control, BAR-file creation, deployment, and Linux-based environments.
Leverage AI-assisted development tools such as Claude Code where appropriate, validating all generated code before implementation.
Required Skills
Strong hands-on experience with IBM App Connect Enterprise (ACE), preferably version 13.
Proficiency in ESQL, SQL, and message-tree manipulation.
Practical experience with IBM MQ, request/reply patterns, and message correlation.
Experience developing REST/SOAP integrations and working with XML, JSON, and XSD.
Database connectivity and SQL programming experience with Oracle, DB2, or SQL Server.
Familiarity with Jenkins, Git, BAR-file deployment, and Linux.
Strong debugging, problem-solving, and communication skills.
Preferred Qualifications
Experience with OpenAPI 3.x, YAML, IBM API Connect, and DFDL.
Exposure to cloud integration, AI bot development, or IBM integration competency labs.
Experience troubleshooting production integration flows and implementing reliable error-handling mechanisms.
Opportunity Details
Work Mode: 100% Remote
Engagement: Part-Time Contract
Availability: Candidates who can commit to agreed project hours and deliverables are encouraged to apply.
Interested candidates can apply through LinkedIn with their updated resume, highlighting their IBM ACE, ESQL, and IBM MQ experience.

Work arrangement
Yes