Mainframe Developer Jobs in Milwaukee, WI (NOW HIRING)

Job Summary:
Northwestern Mutual is a leading financial services company, and they are seeking a Mainframe z/OS Systems Programmer. This role focuses on IBM z/OS environments, where the main responsibilities include system administration, engineering solutions, and mentoring peers in a highly regulated production environment.
Responsibilities:
• Mentor, enable, and teach peers to be self‑sufficient within the mainframe platform
• Apply engineering standard methodologies to analyze, design, and maintain z/OS system‑level solutions
• Leverage established standards, best practices, and automation to support mission‑critical mainframe workloads
• Identify complex system‑level problems and implement reliable, supportable solutions in a highly regulated production environment
• Review, verify, and validate system‑level changes, configurations, and automation introduced into production
• Drive continuous improvement across reliability, availability, performance, security, and operational efficiency
• Develop, maintain, and execute disaster recovery and redundancy strategies
• Partners with vendors and enterprise teams on emerging best practices, patterns, and technologies
• Proactively learn emerging platforms and related technologies
• Establish and maintain best practices related to compliance, security, privacy, and legal requirements
• Anticipate deviations from standard practices and determine practical paths forward
• Track industry trends relevant to the domain and apply them where appropriate
• Break down complex problems into manageable components and help others do the same
• Perform hands‑on z/OS system administration including IPLs, system startup/shutdown, parameter tuning, and system recovery
• Plan, execute, and validate IBM and ISV software installs and upgrades using z/OSMF Software Instances and Workflows
• Manage SMP/E environments including PTFs, HOLDDATA, USERMODs, and consolidation builds
• Install, analyze, and modify system exits and USERMODs, including assembler updates when required
• Build and maintain system‑resident DASD volumes, system libraries, and reproducible system builds
• Configure and administer JES2
• Administer RACF security including users, groups, profiles, access controls, and policy enforcement
• Author, debug, and optimize JCL for batch processing
• Analyze SMF/RMF data for accounting, capacity planning, and system performance tuning
• Administer and tune DFSMS components including DFSMShsm and DFSMSrmm
• Configure and troubleshoot TCP/IP for z/OS and associated services
• Develop automation and tools using REXX, CLIST, and UNIX System Services scripting
• Use monitoring tools such as BMC MainView and/or Intellimagic Vision
• Support mainframe hardware environments including HMC operations, CPC/LPAR configuration, and IBM zSeries platforms
• Participate in on‑call rotations and ITIL‑aligned incident, change, and problem management
• Coordinate with vendors and ISVs for licensing, problem determination, and PTF coordination
• Create and maintain documentation, runbooks, SOPs, and operational procedures
• Mentor and train junior staff on z/OS engineering and operational practices
Qualifications:
Required:
• Bachelor’s degree or equivalent experience
• At least 4 years of relevant experience
• 5+ years of professional IT experience, primarily focused on enterprise mainframe platforms
• Experience applying DevOps concepts, Agile methodologies, and automation in mainframe environments
• Experience monitoring and tuning performance of large‑scale systems
• Working knowledge of scripting or programming concepts for automation
• Familiarity with authentication, authorization, certificates, and vulnerability management
• Extensive hands‑on experience as a z/OS Systems Programmer in production environments
• Strong knowledge of z/OS internals, JES2, RACF, SMP/E, and system libraries
• Proven expertise in SMF/RMF‑based performance tuning, capacity planning, and problem determination
• Experience with DASD, tape management, and SAN technologies, including Hyperswap
• Proficiency with REXX, CLIST, and USS shell scripting (additional languages a plus)
• Knowledge of PKI/SSL, LDAP integration, Kerberos, and mainframe security hardening
• Experience with z/OSMF, Ansible, or automation/orchestration tooling for mainframe lifecycle management
• Strong troubleshooting, documentation, and communication skills under sustained production pressure
Preferred:
• Experience supporting Sysplex and Coupling Facility environments
• Familiarity with cloud‑to‑mainframe integration or CI/CD concepts as applied to z/OS
Company:
At Northwestern Mutual, our financial advisors are ready to meet you where you are and stay with you long-term. Founded in 1857, the company is headquartered in Milwaukee, USA, with a team of 5001-10000 employees. The company is currently Late Stage.