Mainframe Assembler Developer

Mainframe Assembler DeveloperWe 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 ResponsibilitiesAnalyze, 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.Required QualificationsExperience: 8+ years of experience in IBM Mainframe application development and production support.Technical Skills:Assembler (HLASM) programmingJCL/ECL development and troubleshootingTSO / ISPF environmentConnect:Direct (NDM)ISPW (or equivalent change management tools)CA7 schedulingGitHub CoPilotMainframe datasets, VSAM, and utilitiesProfessional Skills:Experience supporting high-volume financial transaction systems and production batch environments with strict SLAs.Experience working in high-availability environments, including Sysplex architectures and multiple LPARs.Understanding of production support processes and incident management.Preferred QualificationsExperience in financial services or banking environments.Prior experience with check processing, image item processing, or payment processing platforms.Familiarity with SMP/E for system maintenance and upgrades.Familiarity with SAR (System Activity Reporter / reporting tools).Experience supporting assembler applications during platform upgrades or macro changes.Everforth Apex Systems is an equal opportunity employer. We do not discriminate or allow discrimination on the basis of race, color, religion, creed, sex (including pregnancy, childbirth, breastfeeding, or related medical conditions), age, sexual orientation, gender identity, national origin, ancestry, citizenship, genetic information, registered domestic partner status, marital status, disability, status as a crime victim, protected veteran status, political affiliation, union membership, or any other characteristic protected by law. Everforth Apex will consider qualified applicants with criminal histories in a manner consistent with the requirements of applicable law.