Job Description

Work Schedule Other
Environmental Conditions Office

As part of the Thermo Fisher Scientific team, you'll discover meaningful work that makes a positive impact on a global scale. Join our colleagues in bringing our Mission to life every single day to enable our customers to make the world healthier, cleaner and safer. We provide our global teams with the resources needed to achieve individual career goals while helping to take science a step beyond by developing solutions for some of the world's toughest challenges, like protecting the environment, making sure our food is safe or helping find cures for cancer.
Job Summary
The Senior Mainframe Operator provides advanced operational support for mission-critical mainframe environments, ensuring high availability, performance, and reliability of enterprise systems. This role acts as a technical escalation point within operations, mentors junior operators, and collaborates closely with system programmers, application teams, and infrastructure support groups to maintain stable production processing.
Key Responsibilities

• Lead day-to-day operation and monitoring of IBM z/OS mainframe systems in a 24x7 production environment
• Serve as the primary escalation point for complex operational incidents and system abnormalities
• Monitor and manage batch processing, online regions, and system resources to meet SLAs
• Analyze console messages, job failures, abends, and performance alerts; take corrective action or escalate appropriately
• Execute and oversee IPL procedures, system restarts, and recovery activities following approved runbooks
• Coordinate closely with system programmers during maintenance windows, upgrades, and incident resolution
• Manage and optimize workload scheduling using tools such as CA7 and CSAR.
• Ensure successful execution of backup, recovery, and disaster recovery processes
• Maintain and improve operational documentation, runbooks, and shift handover procedures
• Mentor and guide junior operators; provide on-the-job training and operational best practices
• Enforce adherence to change management, security, audit, and compliance requirements
• Participate in problem management, root cause analysis, and continuous improvement initiatives

Required Skills & Qualifications

• Bachelor's degree in Information Technology, Computer Science, or equivalent professional experience
• 5+ years of hands-on experience in mainframe operations
• Strong working knowledge of:

• IBM z/OS
• JCL, JES2/JES3
• TSO/ISPF
• Batch scheduling and automation tools
• Proven ability to troubleshoot production issues under pressure
• Strong understanding of operational controls, SLAs, and incident escalation processes
• Excellent written and verbal communication skills

Preferred Qualifications

• Experience supporting large-scale, high-availability mainframe environments
• Working knowledge of mainframe storage (DASD, tape, SMS concepts)
• Familiarity with mainframe security tools such as RACF, and ACF2.
• Experience with ITIL-based operations, incident/problem/change management
• Exposure to automation scripting or workload optimization initiatives

Work Environment

• 24x7 shift-based operations, including on-call responsibilities
• High-impact role supporting business-critical applications
• Requires strong decision-making skills during incidents and outages

Skills Required