Mainframe engineer

Title: Senior IBM z/TPF Systems/Software Engineer

Location: Washington DC - Onsite

Visa: Visa Independent Candidates

Job Description:

Seeking an experienced Senior IBM z/TPF Software Engineer on behalf of a premier client based in Washington, DC. In this role, you will be responsible for designing, maintaining, and supporting mission-critical, high-volume transaction processing applications written in High-Level Assembler (HLASM). Serving as a technical subject matter expert, you will perform deep root-cause analysis, debug complex storage and control block issues, and lead the resolution of production challenges across inventory, reservation, and ticketing workflows. This role offers an exceptional opportunity to collaborate with cross-functional architects and development teams to ensure maximum performance, stability, and production-safe updates for enterprise mainframe systems.

Essential Duties & Responsibilities:

• Application Development & Maintenance: Design, develop, maintain, and support complex IBM z/TPF applications utilizing High-Level Assembler (HLASM/ASM).
• Production Debugging & Diagnostics: Analyze, debug, and resolve high-priority production issues using IBM z/TPF Toolkit, debuggers, dump analysis, and diagnostic utilities.
• Low-Level System Troubleshooting: Perform deep-dive analysis on Entry Control Block (ECB) processing, registers, storage management, work areas, control blocks, masks, flags, and transaction execution flows.
• Database & Record Management: Maintain TPFDF record structures, ordinals, file retrieval/update logic, chain records, and database access paths.
• Macro Analysis & Code Tracing: Trace execution flows generated by macro expansion and investigate underlying functional logic across multiple processing paths.
• Root-Cause & Impact Analysis: Conduct root-cause investigations for inventory, availability, reservation, and ticketing system issues, providing production-safe code fixes.
• Technical Leadership & Collaboration: Perform peer code reviews, mentor development teams, and collaborate with architects and business analysts to translate complex business requirements into technical solutions.
• Documentation & Release Support: Create detailed technical documentation, design specs, and debugging reports while supporting production deployments, testing, and post-release validation.

Minimum Qualifications:

• Education: Bachelor s degree in computer science, Information Systems, Engineering, or a related field (or equivalent practical experience).
• z/TPF & HLASM Experience: 8 years of hands-on experience developing, maintaining, and troubleshooting IBM z/TPF applications and High-Level Assembler (HLASM/ASM) code.
• System Internals & Execution Flows: Deep experience with ECB processing, ECB work areas, registers, storage management, and transaction-processing architecture.
• Debugging Expertise: Proven track record utilizing IBM z/TPF Toolkit, debuggers, dump analysis, and diagnostic utilities to resolve complex production incidents.
• Domain Knowledge: Experience with high-volume transaction-processing systems (e.g., inventory, reservation, availability, ticketing, transportation, airline, or logistics).
• Modern Tools & Methodologies: Proficiency with source control and change management tools (e.g., Git, Jira) and experience working within Agile/Scrum delivery environments.
• Problem-Solving Skills: Excellent analytical, troubleshooting, and collaboration skills with the ability to independently investigate and trace multi-module assembler issues.

Preferred Qualifications:

• Database & File Structures: Hands-on experience with TPFDF record structures, ordinals, file addressing, and chain record processing.
• C / Assembler Integration: Working knowledge of C programming language and C/Assembler integration within z/TPF environments.
• Mainframe Ecosystem Tools: Familiarity with z/OS, TSO/ISPF, JCL, and performance analysis utilities.
• Legacy Modernization: Experience modernizing, refactoring, and optimizing large legacy assembler code bases for high-volume transactions.