zOS Mainframe Consultant
Location: Warsaw, Poland
Job Type: Full time
Contract type : LONG TERM CONTRACT Role
Salary range: EUR 40 – Eur 55 per hour
Work Model: remote (occasional visits to customer office)
Summary
Mainframes process 87% of all credit card transactions and 71% of Fortune 500 data. As our z/OS Consultant, you’ll be the technical expert ensuring these mission-critical systems run flawlessly while architecting innovative solutions that bridge legacy power with modern agility.
You’re not just a mainframer or just a programmer—you’re someone who sees the big picture. You understand that great mainframe work requires both the precision of coding elegant programs and the strategic thinking of system architecture. You’re curious about modernization, excited about solving complex puzzles, and eager to work with technology that processes billions of transactions daily.
Roles & Responsibilities
Programming Excellence
Design, develop, and optimize mainframe applications using COBOL, PL/I, Assembler, or REXX
Build and enhance batch processing systems and real-time transaction applications
Implement DB2 database solutions with complex SQL queries and stored procedures
Create efficient JCL procedures and utilities that streamline operations
Develop APIs and integration points connecting mainframe systems with modern cloud platforms
System Administration Mastery
Configure and maintain z/OS operating system components (JES2/JES3, RACF, SMS, DFSMS)
Perform system tuning, capacity planning, and performance optimization
Manage storage subsystems, datasets, and VSAM file structures
Implement security protocols and audit compliance measures
Oversee system upgrades, patches, and disaster recovery procedures
Hybrid Innovation
Bridge mainframe capabilities with distributed systems and cloud environments
Modernize legacy applications while maintaining system stability
Automate repetitive tasks using scripts and modern DevOps practices
Mentor teams on mainframe best practices and emerging technologies
Required Skills & Qualifications
Required Skills
4+ years of hands-on z/OS experience
Strong programming skills in at least two: COBOL, PL/I, Assembler, REXX, or Assembler
Solid understanding of JCL, utilities (IEBGENER, SORT, IDCAMS), and batch processing
Experience with system administration tasks (dataset management, security, job scheduling)
Knowledge of DB2, IMS, CICS, or MQ middleware
Problem-solving mindset with attention to detail
Highly Valued
Exposure to modern mainframe tools (Zowe, z/OSMF, Git for z/OS)
Understanding of DevOps practices and CI/CD pipelines
Experience with performance monitoring tools (RMF, SMF, Omegamon)
Knowledge of networking protocols and subsystem integration
Scripting abilities in Python, Shell, or similar languages
Experience with mainframe-to-cloud integration projects
Certifications (Preferred, but not mandatory)
IBM Certified System Administrator – z/OS
IBM Certified Application Developer
COBOL or DB2 certifications