Mainframe Modernization Engineer

Doran Jones Inc. • Dallas, TX

7d

About The Position

We are seeking a Mainframe Modernization Engineer to support a large-scale legacy transformation initiative to modernize COBOL-based systems into contemporary Java applications. This is a hands-on engineering role focused on deep analysis of existing mainframe batch programs, active participation in modernization workflows, and close collaboration with Java engineering teams to ensure functional accuracy and performance throughout the transformation. You will work directly with legacy codebases and modernized outputs, contributing technical insight that improves both code quality and modernization tooling.

Requirements

• 5–8 years of hands-on experience working with COBOL on IBM mainframe environments.
• Strong experience with JCL, DB2, and VSAM.
• Hands-on experience supporting and analyzing mainframe batch jobs.
• Proven ability to analyze complex COBOL logic and map it to equivalent behavior in modern applications.
• Solid understanding of testing methodologies, validation techniques, and defect analysis.
• Strong analytical skills and attention to detail when reconciling outputs across systems.

Nice To Haves

• Experience participating directly in large-scale legacy modernization or platform transformation initiatives.
• Exposure to Java, including Java on mainframe environments such as z/OS.
• Prior experience participating in COBOL-to-Java transformations or legacy modernization initiatives.
• Experience working alongside platform or tooling teams supporting automated code transformation.

Responsibilities

• Analyze and interpret legacy COBOL batch programs running on IBM mainframes, including programs utilizing JCL, DB2, and VSAM.
• Understand and document functional logic, control flow, and data transformations to support modernization efforts.
• Review and validate automatically generated functional documentation for accuracy, completeness, and alignment with actual program behavior.
• Design and execute test cases to validate business logic and ensure output consistency between legacy and modernized systems.
• Compare Java program outputs against original COBOL program results to identify discrepancies.
• Collaborate with modernization and Java development teams to resolve mismatches and refine generated code.
• Participate in transformation quality assurance activities and contribute to continuous improvement of the modernization platform.

What This Job Offers

• Job Type: Full-time
• Career Level: Mid Level
• Education Level: No Education Listed
• Number of Employees: 51-100 employees