IBM z/OS Experts
matched in minutes from over 15,000 CVs with the power of AIHire experts who keep IBM z/OS systems stable, modernize JCL and batch flows, and support CICS, Db2, and RACF work across mainframe estates. Get fast, precise matching with vetted, available freelancers.
Meet FRATCH Experts who have recently used IBM z/OS
Robert Karash
Last position:
Interim Manager | Group Leader in the IT Operations & Digitalization Division "Databases, Operations & Support" (DOS) at Landwirtschaftliche RentenBank
- Technical leadership and further development of a team of 28 IT staff (internal & external) in the areas HelpDesk/HelpLine, RHEL (Red Hat), MUREX (trading system & applications), SAP basis operations
- Managing external service providers (including FI-TS for SAP basis operations)
- Personnel, resource and budget planning for the IT department and projects
- Introducing and establishing regular communication formats (weekly status meetings, team and cross-department meetings)
- Ensuring application operations in a hybrid environment (Windows/Linux with database and web/application servers)
- Supporting transformation projects to modernize the application landscape (e.g. DevOps approaches)
- Setting up and implementing a digital IT procurement for hardware & software (e.g. with DELL)
- Developing and managing the "IT Operations DOS" department based on corporate strategy
- Preparing management reports & decision papers on IT projects, optimization potential and automation opportunities
- Representing the department in the advisory boards of the Rentenbank and ensuring regulatory compliance (BaFin §44, GDPR, BSI, MaRisk)
Tezcan Dilshener
Last position:
Solution Architect / Project Manager at German Football Association
- Overall responsibility for the project lifecycle from scope definition to completion
- Close collaboration with platform teams, IT leaders, and external service providers
- Application of SAFe principles and structured sprint work
- Creation of a migration roadmap with clear milestones
- Monitoring of the lifecycle: onboarding, repository migration, replication of permissions, and system tests
- Visualization of the architecture with PlantUML and Gliffy as well as documentation in Confluence
- Regular status reports and running knowledge transfer sessions
Birgit Stünkel
Last position:
Business Analysis, Requirements Engineer at BMW
Refinement of epics and user stories to achieve a higher degree of automation in CRM usage. Testing of new Discountsystem
Alex Volnov
Last position:
CTO, Co-Founder, Cryptography(incl. Post-Quantum Cryptography) and AI Security Expertise at AISLEIPNIR
- Integration of Post-Quantum Cryptography (PQC) algorithms into high level protocols.
- Security of implementations of Post-Quantum Cryptography algorithms.
- Transition to Post-Quantum public key infrastructures.
- Security evaluations of Post-Quantum Cryptography (PQC) primitives.
- Drone Cybersecurity
- Satellite Cybersecurity
- AI Security
Mario Techera
Last position:
Project Lead/Manager / Consultant at all-BI GmbH
- Establishing the Microsoft Fabric platform with the company as the central data warehouse and reporting system.
- The company migrated several operational systems including D365 to new version. The new data warehouse is based on a Fabric/Power BI architecture with Azure cloud Entra Authentication.
Tasks Performed:
- Full administrative responsibility for the Fabric platform F64 and F32 capacities, as well as two F8 capacities for development and prototyping.
- Integration of Fabric with Microsoft Entra.
- Data modeling for the data warehouse bronze, silver and gold layers using data modeling tools.
- Star Schema as well as entity relationship modeling.
- Data modeling for data marts and for dimensional modeling and Power BI (semantic model).
- Design of data models for Microsoft SSAS multidimensional and tabular OLAP cubes using DAX and MDX.
- Definition of design patterns for the ETL team for loading OLAP cubes (Tabular and MD), star schemas and data vault structures.
- Planning and managing team of 4 ETL and reporting developers.
- Performance Tuning of Power BI reports, particularly the semantic layer, as well as the Fabric notebooks
- SQL Performance Tuning.
- DB Design for Azure SQL.
- Reporting directly to project senior management.
Label: Power BI, Fabric, Analysis Services (multidimensional and tabular), D365, SSIS, Tabular Editor, SQL Server and Azure SQL, TOAD Data Modeler, DBSchema, Visual Studio Code, DAX Studio, SSMS, Visual Studio, Jira and Confluence.
Matthias Ottowski
Last position:
IT Project Manager at IT service provider
Implementation of anti-money laundering requirements in accordance with AMLA/KYC for an international large bank in Munich
Services provided:
- Clarification of the assignment, definition of the work package structure for the AMLA/KYC implementation project
- AI-supported project planning using my own AI workflow for project management
- Creation of the project management plan
- Resource and capacity planning
- Development of collaboration structures between IT service provider and bank client
- Alignment of responsibilities (RACI matrix)
- Management of 5 project members (core team)
- Project control, project monitoring, project reporting
- Communication management
- Escalation management
- Stakeholder management (11 stakeholders)
- Permanent member of the steering committee
- Project representation internally and externally
- Project reporting, management of decision-making bodies
- Project volume: 506 person-days (development effort)
- Risk management
- Quality management
- Organization and running of workshops
Methods: PMI PMBOK, EVM, GWG, DORA, BAIT, KANBAN, AML, AMLR, AMLA, GWG, KYC
IT environment: JIRA, Confluence, Sharepoint, Kantata Kimble, AI LLM Copilot, ChatGPT, anti-money laundering systems (in-house developments and SMARAGD)
Timo Heck
Last position:
Software Developer at Continentale Krankenversicherung AG
- Implementation of a REST-based web service for querying contract, claims, customer, and sales data as part of the Dialogmanager project.
- Data release is done in compliance with CoC requirements and individual user permissions from IAM (Identity and Access Management).
- Implementation using JBoss EAP 8.1 (JakartaEE 10) and Java 21 as well as JAX-RS, CDI, Microprofile-Config, Microprofile-OpenAPI.
Sven Hummel
Last position:
Process Architect (Symbio, Signavio) at IT service provider for an international premium automaker
- Analyzing, aligning and modeling business processes (BPMN 2.0) for the 'The New Retail' program in the areas of invoicing, tax, customs and accounting
- Tracking user stories and their impact on processes
- Point of contact for preparing the tool migration from Symbio to Signavio for the mentioned areas
- Power user after the introduction of Signavio, point of contact and coach for other process modelers
Vladimir Ergovic
Last position:
Technical Project Manager / Freelancer at Deutsche Bank
- Engaged within the Information and Security Management division for a Proof of Concept (PoC) project focused on developing a Client Security Portal.
- Managed project resources across the UK, India, and Germany.
- Architected and deployed the PoC solution leveraging a modern Java stack, Google Cloud Platform (GCP) with Kubernetes, and Active Directory (Entra ID) for authentication.
- Implemented OAuth 2.0 for authorization.
- Ensured DORA alignment according to Deutsche Bank security rules and regulatory preparation.
Tobias Rudolph
Last position:
M&A IT Project Manager / Cross-functional Technical and Integration Manager at Sandoz AG
- Worked for several M&A projects (Eire, Sunshine C, Coral) in the role of IT project manager and cross-functional technical manager / integration manager.
- Preparation and maintenance of project charters, project change requests and project plans.
- Weekly project status report.
- Preparation of decision papers and steering committee slidedecks.
- Risk & issue management.
- Tracking and managing activities, dependencies and deliverables across all functional IT domains.
- Data migration (planning and execution).
Ulm Paunel
Last position:
DataStage ETL Expert at ING Bank
- Datastage 11.7, dbt, Oracle 19, Python 3.12 / PySpark 3.5, Azure GitHub, Azure DevOps, Automic
- Development of migration jobs to transfer data from the collection DWH to the new Risk Mart, as well as development of ETL pipelines to migrate historical data from the old Mart to the new Risk Mart.
- Storage of the silver layer on Hadoop and the gold layer in Oracle.
- Translation of DataStage jobs into dbt to publish reporting data in Google Cloud to a PostgreSQL database.
- Creation and optimization of complex SQL queries for data extraction from a data vault, taking into account historical data in the point-in-time tables.
- Creation of Oracle table definitions (DDL) and adjustment of existing stored procedures.
- Versioning changes in GitHub and deployment via the CI/CD portal.
- Refactoring long-running DataStage jobs into Python using PySpark to reduce server load.
- Migration of SAS scripts to PL/SQL, including new development of distribution functions that have no direct equivalent in Oracle.
- Development of Automic jobs to run DataStage pipelines and Python scripts (PySpark jobs) that control the population of the SME and institutional risk tables in the Risk Mart and perform business calculations.
- Participation in the agile process, including creating user stories, estimations, and planning in Azure DevOps.
- Handling Azure DevOps tickets and close collaboration with testers and business teams for error analysis and resolution.
Klaus Ewers
Last position:
Exasolution DBA at Rechenzentrum Innsbruck
- DBA Exasolution Server consulting and migration to version 8
- Analysis of SQL query performance and tuning
- Troubleshooting in batch scripts
- Technologies: Gitlab, EXACloud, EXAOperation, DBeaver, Control M
Hans-Dieter Große-Kreul
Last position:
Training as an AI Expert
I continuously expand my expertise in AI and automation, working with ChatGPT, OpenAI, Manus, Gemini, MS CoPilot, API, LangChain, Hugging Face, Manus, TensorFlow and Auto-GPT as well as Python-based ML frameworks and MLOps tools to intelligently transform classic software development, analysis, and testing processes.
Hartmut Ullrich
Last position:
Freelancer at Freelancer
Projects at Raiffeisen Software Group (RSG), Linz from 2022-01-01 to 2025-03-31: application development on mainframe with PL/1, DB2, JCL, Tabex; development environment with idz, Jira, Dimensions, Confluence; execution of projects in banking reporting (own funds, capital requirements, large exposures, leverage ratio)
Project at Airbus, Hamburg from 2020-01-01 to 2022-12-31: mainframe system enhancements (TAKSY) in agile environment (Scrum, SAFe); business analysis; technical design; implementation (PL/1, DB2, IMS, JCL); test management; deployment
Sebastian Hefczyk
Last position:
Overall Project Manager; Turnaround Manager & Coach at Statutory Health Insurance Fund
- Taking over the troubled project from the internal project management and successful turnaround of project phase 1 (cutover of approx. 1000 servers (VMs)/standard desktops, specialized desktops)
- Responsible project management for the successful phase 1 transition (planning in the shortest possible time followed by implementation (very successful with low ticket volume))
- Stakeholder management – taking over direct (daily before cutover) communication with the client from the Chief Operation Manager in the format of regular meetings in taskforce mode. Rapid rebuilding of the previously lost trust base and restoration of the client relationship for optimal satisfaction
- Taskforce mode to eliminate all existing issues/showstoppers before cutover
- Scope clarification, setup, and scheduling of phase 2 activities (e.g. silo/admin servers)
- Kick-off of phase 2 / handing the project back to the success line for the internal project management/line to handle the remaining defined topics
- Establishing, preparing, and conducting steering committees with V-1 management to align the guardrails
- Moderation of various regular meetings and operational workshops
- Participation in the lessons learned with the client to address dissatisfaction related to the internal project management (before my start! They are extremely satisfied with my work)
- Tools: Atlassian Suite (Confluence/JIRA), MIRO, Sharepoint; MS Office (PowerPoint, Excel, MS Project)
Discover over 15,000 top freelancers
Statistics of experts using IBM z/OS
Aggregated from the professional profiles of matched freelancers.
Experience
31 years
Position duration
1.9 years
Positions per freelancer
19
Top business areas
Information Technology, Project Management, Quality Assurance
Top industries
Information Technology, Banking and Finance, Insurance
Certification focus areas
Information Technology, Project Management, Quality Assurance
Bachelor's degree or higher
65%
Master's degree or higher
46%
Doctorate
17%
Certifications per freelancer
3
Most common languages
German, English, French
Speak two or more languages
95%
Based on our profile pool as of 6 Sep 2026.
Daily rate distribution
The chart shows how the daily rates of freelancers in this technology are distributed, based on recent contracts on our platform. Each bar covers a rate range — its height shows how many freelancers charge within that range.
Average rates of experts using IBM z/OS
Rates are based on recent contracts and do not include FRATCH margin.
The average daily rate is the mean of all daily rates from recent contracts of comparable freelancers on our platform.
The median daily rate is the middle value of all daily rates — half of comparable freelancers charge less, half charge more. Unlike the average, it is barely affected by outliers.
Calculated based on our freelancers’ daily rates as of 6 Sep 2026. Actual rates may vary depending on seniority level, experience, skill specialization, project complexity, and engagement length.
About the technology
Core platform
IBM z/OS is the operating system behind many enterprise mainframes. It runs core workloads that need high availability, strict control, and strong transaction handling. Companies use it for payment processing, policy systems, batch jobs, and other critical back-end services.
Typical work
- JCL and batch job maintenance
- CICS transaction support
- Db2 for z/OS application work
- RACF security and access control
- System upgrades, tuning, and incident recovery
Ecosystem
z/OS work often sits next to COBOL, PL/I, Assembler, CICS, Db2, IMS, VSAM, and SDSF. Strong professionals understand how programs, jobs, security rules, and data sets fit together. They also know how to read logs, traces, spool output, and scheduler results without slowing production.
When to bring in help
Companies bring in freelance IBM z/OS specialists when a release is stuck, a batch window is slipping, or a legacy application needs careful change. They also help during audits, migrations, capacity work, and team handovers. In Germany, this is common for banks, insurers, industry groups, and public-sector systems that still depend on mainframe stability.
What strong specialists do
A strong z/OS professional works methodically and documents changes clearly. They protect existing behavior, test under realistic conditions, and understand the impact of one job, one dataset, or one security rule on the wider system. They can collaborate with application specialists, operations teams, and security stakeholders without creating extra risk.
Engagement fit
z/OS projects often need people who can work remotely, review existing control decks and job streams, and step in on-site when access or change windows require it. The best fit is someone who can read unfamiliar mainframe logic quickly and keep production safe. That matters when the environment is old, complex, and still business critical.
Frequently asked questions
Questions about IBM z/OS? Start with the answers below.
IBM z/OS runs the mainframe workloads that companies cannot afford to interrupt. It is used for high-volume transactions, batch processing, core records, and tightly controlled enterprise operations. You usually find it in banking, insurance, retail back offices, and other systems where stability matters more than change speed.
z/OS is built for centralized, high-reliability mainframe computing, not general server hosting. Compared with Linux or Windows, it relies more on job control, dataset management, and mainframe security and operation concepts. Companies choose it when they need proven control over very critical workloads.
A strong IBM z/OS specialist usually knows JCL, CICS, Db2, RACF, and common mainframe utilities. COBOL or PL/I reading skills are often important because many changes touch existing application logic. Good specialists also understand scheduling, dump analysis, and how to work with operations teams.
Yes, because even a small change can affect batch timing, security, or shared datasets. z/OS environments often have many connected jobs and older dependencies that are not obvious at first glance. An experienced specialist helps avoid regression, delays, and production issues.
Much of IBM z/OS work can be done remotely if access, tools, and security controls are in place. Specialists can review JCL, investigate logs, tune jobs, and prepare changes off-site. On-site presence is still useful when production access, secure hardware, or tight change windows require it.
Look for clear explanations, careful change notes, and a calm approach to production risk. A good z/OS freelancer can show how they diagnosed a problem, what they changed, and how they verified the result. If they speak precisely about dependencies, datasets, security, and scheduling, that is a strong sign.
IBM z/OS is the operating system that runs on IBM mainframes, so the terms are related but not identical. People often say “mainframe” when they mean the whole platform, while z/OS refers to the operating system layer. That distinction matters when you are hiring for OS work versus application or hardware tasks.
Projects around IBM z/OS often include upgrades, performance tuning, incident recovery, security changes, migration planning, and batch stream cleanup. Teams also need help when they modernize parts of a legacy estate without disturbing core processing. The best specialists keep the system stable while the business changes around it.
The average hourly rate of freelancers who have used IBM z/OS in their recent projects is 101 €, which corresponds to a daily rate of about 808 € based on an 8-hour working day.
Of the freelancers who have used IBM z/OS in their recent projects, 65% hold at least a Bachelor's degree, 46% hold at least a Master's degree, and 17% hold a doctorate.
On average, freelancers who have used IBM z/OS in their recent projects have 31 years of professional experience, with a single engagement typically lasting around 1.9 years.
The most common languages among freelancers who have used IBM z/OS in their recent projects are German (100%), English (95%), and French (26%).
The most common industries among freelancers who have used IBM z/OS in their recent projects are Information Technology (91%), Banking and Finance (89%), and Insurance (63%).
The most common business areas among freelancers who have used IBM z/OS in their recent projects are Information Technology (100%), Project Management (77%), and Quality Assurance (77%).
Main locations of FRATCH Experts, who have recently used IBM z/OS
Our freelancers and interim experts are at home across the DACH region — available on-site in the major business hubs or fully remote. Choose a location to discover matched specialists, local market insights and up-to-date availability.
Berlin Hamburg Munich Cologne Frankfurt Stuttgart Dusseldorf Leipzig Dortmund Essen Bremen Dresden Hanover Nuremberg 
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FRATCH CEO
