Mainframe Developer – CICS / z/OS

N Consulting Limited; Greater London; Hybrid; GBP 55,350 - 64,575; Part time

Job summary

N Consulting Limited is seeking a Mainframe Developer with experience in IBM Mainframe technologies, including CICS, z/OS, and COBOL, to work on critical banking applications. The role involves development, maintenance, and optimization of legacy systems, with a focus on performance tuning and production support. Candidates should have strong skills in DB2, IMS, and experience with Agile methodologies. This is a contract position based in London, offering a hybrid work model.

Qualifications

• 5+ years of experience in Mainframe development with expertise in IBM technologies.
• Strong troubleshooting and performance tuning skills required.
• Experience in production support and incident management.

Responsibilities

• Develop, maintain, and enhance applications on IBM z/OS platform.
• Optimize SQL queries and perform DB2 performance tuning.
• Support online and batch processing environments.

Skills

IBM Mainframe

z/OS

CICS

COBOL

JCL

DB2

IMS

VSAM

Control-M

Cloud Integration

Tools

Endevor

ChangeMan

File-AID

Expeditor

SDSF

Job description

LocationLondon, United Kingdom# Mainframe Developer – CICS / z/OS at N Consulting LtdLocationLondon, United KingdomSalary£300 - £350 /dayJob TypeContractDate PostedApril 30th, 2026Apply Now**Job Description**Infosys is seeking an experienced **Mainframe Developer** with strong expertise in **IBM Mainframe technologies**, including **CICS, z/OS, COBOL, JCL, DB2, IMS, and VSAM**, to support enterprise-critical banking and financial applications. The candidate will work on development, enhancement, maintenance, and modernization of legacy mainframe systems while ensuring system stability, scalability, and performance.**Key Responsibilities*** Develop, maintain, and enhance applications on **IBM z/OS** platform* Design and code programs using **COBOL, JCL, CICS, DB2, IMS, and VSAM*** Support both **online (CICS)** and batch processing environments* Perform debugging, root cause analysis, and resolution of production issues/abends* Optimize SQL queries and DB2 performance tuning* Work with schedulers such as **Control-M / CA7 / TWS*** Participate in application modernization initiatives including API enablement and cloud integration* Collaborate with business analysts, testers, architects, and offshore teams* Follow Agile/Scrum methodology and CI/CD practices**Required Skills*** Strong hands-on experience with: + IBM Mainframe / **z/OS** + **CICS Transaction Server** + COBOL, JCL + DB2 / IMS + VSAM + MQ Series* Experience with tools: + Endevor / ChangeMan + File-AID + Expeditor / Xpediter + Abend-AID + SDSF / SPUFI / QMF* Strong troubleshooting and performance tuning skills* Experience in production support and incident management**Job Title: Mainframe Developer – CICS / z/OS** **Location: London, UK (Hybrid)** **Experience: 5+ Years** **Employment Type: Contract**