Senior Mainframe IBM z/OS developer (willingness to learn Assembler)

Description & Requirements Who we are looking for We are looking for an experienced Mainframe Developer to support our clients in system development, maintenance, and modernization initiatives. The ideal candidate will possess a thorough understanding of IBM z/OS, mainframe architecture, and related technologies.

• Proficient in Assembler/Cobol programming and mainframe environments, including IBM z/OS (willingness to learn Assembler if Cobol is your main programming language)
• Minimum of 4–5 years’ experience in Assembler/Cobol development, with at least 3 years working on mainframe systems
• Hands-on experience with DB2
• Experienced with performance and debugging tools
• Strong understanding of memory management and system-level programming concepts
• Proven ability to troubleshoot and resolve complex production issues effectively
• Excellent command of English,Polish at least B2 level
• You need to be located in Poland with valid work permit

Nice to have:

• Skilled in integrating Assembler code with COBOL, PL/I, or Java applications
• IBM Certified System Programmer and z/OS Mastery certifications are advantageous

Your future role

• Develop, test, and optimize Assembler code for mainframe environments.
• Maintain and improve existing legacy Assembler applications to align with evolving business requirements.
• Work closely with cross-functional teams to integrate Assembler modules with COBOL and Java systems.
• Enhance system performance by utilizing monitoring tools such as IBM RMF and OMEGAMON.
• Diagnose and resolve complex technical issues through advanced debugging techniques.
• Provide guidance and mentorship to junior developers, facilitating knowledge exchange sessions.
• Participate in planning and executing system modernization initiatives and technology upgrades.

What we offer

• A budget to spend on benefits that suit you, on top of your salary.
• Open colleagues, an environment that encourages proactivity, creativity, cooperation and openness.
• Contribution to practice development by shaping fit-for-purpose approaches and methodologies for Deloitte clients.
• Fast-paced development in a dynamic, high growth environment.
• Work with Deloitte clients locally and globally, delivering high-impact solutions to complex challenges and helping them drive exceptional performance.

Selection process Stage 1 - Send your CV in pdf format in English.

Stage 2 - Join an HR screening

Stage 3 - 2 interviews: technical one and on the business side

About Deloitte In Deloitte we support leading global organizations in optimizing and transforming their organizations. This also relates to their finance function. Our consultants offer insights, capabilities, and solutions that change the way these organizations operate and make people-related decisions.

We are currently building in Poland a dedicated team which will focus on advisory in the area of Finance & Performance. The Team will advise our Clients in complex issues relating to i.a. Reporting, Budgeting, Controlling processes. We are looking for high-energy, committed and ambitious people to join our advisory practice. Next to advising on most sophisticated and challenging issues relating to the above mentioned areas, our Consulting professionals will also advise on potential solutions leading to optimisation of the above mentioned processes. This will also include applying the newest technologies.

Are you ready to join our team and help our clients imagine, deliver, and run their future?