Senior Mainframe Network Systems Engineer

Overview

Ob Description

Job Title: Senior Mainframe Network Systems Engineer

Location
:
Remote

About the Role: Heitmeyer is seeking a seasoned Senior Mainframe Network Systems Engineer to design, maintain, and optimize mission-critical mainframe networking for a financial services client. This role is responsible for high availability, security, performance, and resiliency of IBM z/OS environments and the network services that connect them to distributed, cloud, and external partners. This role is hands-on and collaborative—working closely with infrastructure, application, security, and operations teams to ensure reliable transaction processing and batch workloads at scale.

• Diagnosis and solve for latency issues on the Mainframe
• Diagnoses issues with transmission coming in and going out of the mainframe using SSL TLS and Tracing.
• Mainframe Networking & Connectivity
• Architect, configure, and support z/OS TCP/IP, SNA, VTAM, TN3270, and Enterprise Extender (EE) services.
• Manage IP routing, OMPROUTE/Policy-Based Routing, and network stacks across LPARs.
• Integrate mainframe networking with enterprise load balancers, firewalls, and DNS/DHCP/IPAM.
• Systems Integration & Middleware
• Support and optimize IBM MQ, CICS transaction servers, and DB2 connectivity (DDF, DRDA).
• Ensure secure, high-throughput data exchange between mainframe and distributed/cloud platforms (APIs, MQ queues, FTP/SFTP, Connect:
  
  Direct).
• Performance, Capacity, and Reliability
• Monitor and tune network stacks, sockets, buffer pools, and Hiper Sockets; analyze OMEGAMON/Net View data for bottlenecks.
• Lead capacity planning and performance engineering for peak cycles, batch windows, and online transaction processing.
• Security & Compliance
• Implement and enforce security controls (TLS/AT?
  
  TLS, IPSEC, RACF/ACF2/Top Secret, firewall rules).
• Partner with Info Sec and Audit to meet regulatory and policy requirements (e.g., PCI DSS, FFIEC, SOX).
• High Availability & Disaster Recovery
• Design and test HA/DR architectures (Parallel Sysplex, GDPS, XCF, multi-site networking, data replication).
• Coordinate failover exercises; document runbooks and recovery procedures.
• Incident Response & Root Cause Analysis
• Own complex troubleshooting across layers (network, OS, middleware, application).
• Lead post-incident reviews; implement durable fixes and preventive monitoring.
• Automation & Observability
• Develop scripts and automation for configuration management, monitoring, and reporting (REXX, JCL, CLIST, Ansible/Z, or equivalent).
• Create dashboards and alerts for key network and transaction health indicators.
• Project Leadership
• Serve as technical lead for infrastructure upgrades, core application releases, and environment migrations.
• Coordinate with application owners, vendors, and PMO; deliver clear technical documentation and status updates.

• 10+ years of experience in mainframe systems/network engineering within large enterprises.
• Deep expertise with IBM z/OS networking (TCP/IP, SNA/VTAM), CICS, DB2, and IBM MQ integration.
• Strong knowledge of LPARs, Sysplex, JES2/JES3, and z/OS operating internals.
• Hands-on experience with network security on z/OS (AT?
  
  TLS, IPSEC, RACF/ACF2/Top Secret).
• Proven track record in performance tuning, capacity planning, and HA/DR for mission-critical environments.
• Proficiency with monitoring tools (e.g., OMEGAMON, Net View, SDSF, RMF) and packet/trace analysis (IPCS, PKTTRACE).
• Scripting and automation: REXX, JCL, CLIST (Python/Ansible a plus).
• Excellent communication skills; able to explain complex issues to technical and non-technical stakeholders.
• Bachelor’s degree in Computer Science, Information Systems, or related field (or equivalent experience).

• Experience in financial services/banking and high-volume transaction processing.
• Familiarity with z/OS Communications Server, Enterprise Extender, Hiper Sockets, and OSA-Express.
• Knowledge of API integration patterns and secure partner connectivity.
• Exposure to cloud connectivity (private links, gateways) integrating with mainframe data/services.
• Certifications:
  
  IBM z/OS, ITIL, Security, PMP or equivalent.