Mainframe Assembler Developer

Location: Hybrid in Addison, TX or Charlotte, NC (3 days in office 2 days remote) Relo candidates are fine


We just got a new req with Client for a Mainframe Assembler Developer. Full details are below. We have a call with the manager later this afternoon to setup interviews so let's try to get some candidates over by then.

We are seeking a highly experienced Mainframe Assembler Developer to support and enhance a mission-critical legacy application written in IBM z/OS assembler language. This role requires a self-sufficient engineer capable of independently analyzing, maintaining, and improving high-volume, high-availability batch processing systems in a regulated financial services environment. The ideal candidate brings deep expertise across core mainframe technologies and strong familiarity with parallel sysplex environments.

Key Responsibilities

• Analyze, maintain, and improve high-volume, high-availability batch processing systems.
• Provide production support for IBM Mainframe applications.
• Develop and troubleshoot JCL.
• Manage GDGs and batch processing to meet strict SLAs.
• Work independently within loosely documented legacy environments.
• Analyze complex assembler codebases to diagnose and resolve critical production issues.
• Handle incident management using tools like ServiceNow or Remedy.

Experience: 5+ years of experience in IBM Mainframe application development and production support.

Technical Skills:

• Assembler (HLASM) programming
• JCL/ECL development and troubleshooting
• TSO / ISPF environment
• Connect:Direct (NDM)
• ISPW (or equivalent change management tools)
• CA7 scheduling
• GitHub CoPilot
• Mainframe datasets, VSAM, and utilities