Principal Mainframe Developer - HLASM

Role overview This is a deeply specialized mainframe engineering role focused on building high-performance, low-level instrumentation inside CICS and z/OS environments. You will join a small, highly experienced team developing AI-driven observability features that ship into some of the most demanding production systems in the world, where every cycle of overhead matters.

Responsibilities - Build low-level, high-performance instrumentation inside CICS and z/OS using HLASM. - Design and ship features that power observability for the largest enterprise customers. - Diagnose complex runtime behavior by reading dumps, traces, and other deep system artifacts. - Deliver code that meets strict performance and overhead constraints in mission-critical environments. - Collaborate closely with a small, elite team of experienced engineers and raise the technical bar across the group.

Requirements - 7+ years of real-world HLASM experience. - Deep expertise in z/OS internals, CICS internals, systems programming, and runtime behavior. - Strong, hands-on experience with CICS. - Daily proficiency with JCL, SDSF, and USS. - Proven ability to analyze dumps, traces, and performance bottlenecks down to the instruction level. - Working knowledge of COBOL, PL/I, or C for testing and debugging.

Nice to have - Experience with DB2, MQ, networking, CTG, security, or WebSphere (WAS). - Familiarity with z/OS Connect or modern hybrid mainframe architectures. - Some Java or AI experience.

Benefits and work setup - Salary range of $161K – $241K depending on experience and location. - Health, dental, life, short-term and long-term disability coverage, 401(k), and PTO.