Mainframe API Developer (z/OS Connect EE & CICS Web Services)

We are looking for a highly skilled Mainframe API Developer with strong expertise in z/OS Connect EE and CICS Web Services to join our growing team. If you are passionate about modernizing legacy systems and building robust API solutions, this role is for you!

Job Title: Mainframe API Developer (z/OS Connect EE & CICS Web Services)

Location: London, UK

Work Mode: Onsite

Key Responsibilities:

✔ Design, develop, and maintain mainframe APIs using z/OS Connect EE and CICS Web Services

✔ Implement SOA and RESTful architecture patterns

✔ Develop and support COBOL/DB2 programs and JCL batch processes

✔ Work with tools like FileAid, Xpeditor, IBM Explorer for z/OS API, and Visual Studio

✔ Drive modernization of legacy mainframe services into scalable APIs

Code Quality & Optimization:

✔ Ensure high code quality and adherence to standards

✔ Optimize DB2 queries and database access

✔ Implement robust error handling and logging mechanisms

API Development & Integration:

✔ Build and support APIs using SOAP, WSDL, and JSON

✔ Define service contracts and perform payload mapping & transformation

✔ Validate end-to-end API workflows across systems

Collaboration & Support:

✔ Work closely with testers, architects, and product teams

✔ Troubleshoot production issues and resolve defects

✔ Improve API design, scalability, and maintainability

DevOps & CI/CD:

✔ Integrate code with GitLab CI/CD pipelines and UCD

✔ Follow best practices in GitLab and Endevor source control

✔ Support continuous integration and delivery

Security & Compliance:

✔ Implement API security (Basic Auth, mTLS, OAuth)

✔ Manage CICS transaction security configurations

✔ Handle RACF rules, access control, and security coordination

✨ Nice to Have:

• Exposure to AI-driven development

• Experience in API automation and testing