Senior Mainframe Developer / COBOL Senior Consultant

Job Title: Senior Mainframe Developer / COBOL Senior Consultant
Contract Start & End Date: ASAP - 11/11/2026 (will be extended)
Onsite or remote: Onsite
Worksite address: Trenton, NJ

*Local Candidates only. Candidates should have strong background in Cobol, ADABAS, and Natural. strong in JCL as well.

Job Description

We are looking for a Senior Mainframe Developer / COBOL Senior Consultant to evaluate existing systems and user needs in order to analyze, design, recommend, and implement information system changes. This position will be a contract role and is onsite in Trenton, NJ.

What You ll Do

• Participate in development efforts supporting the project involving multiple legacy mainframe applications

• Analyze existing legacy systems and provide code walkthroughs, logic analysis, and technical documentation to ITS development teams

• Design, develop, modify, test, and maintain COBOL and NATURAL programs, along with associated JCL jobs, based on functional specifications and enhancement requests

• Perform ongoing maintenance and enhancements to batch and online mainframe applications

• Troubleshoot and resolve production issues, job failures, and system abends, including root cause analysis and corrective actions

• Analyze ADABAS database structures, files, and access methods to support application development and system integration

• Develop and maintain data feeds, file layouts, and interface processes between legacy systems and modernized ITS components

• Participate in system design reviews, technical planning sessions, and code reviews

• Produce and maintain technical documentation, including program specifications, data definitions, job flows, and system architecture documentation

• Support system testing, integration testing, and user acceptance testing UAT

• Implement best practices for mainframe development, including coding standards, version control, and change management

• Assist with performance tuning and optimization of batch jobs, database access, and program execution

• Provide production support for missioncritical applications and collaborate closely with analysts, architects, and development teams

What You ll Need

Required:

• Advanced experience with COBOL programming in enterprise mainframe environments

• Strong expertise in JCL development and job scheduling

• Extensive experience with NATURAL programming

• Working knowledge of ADABAS database architecture and file structures

• Experience analyzing and maintaining large legacy mainframe codebases

• Strong troubleshooting and debugging skills for batch and online applications

• Experience with system integration, data interfaces, and file transfer processes

• Proficiency with mainframe utilities, debugging tools, and job monitoring tools

• Strong documentation and communication skills

• Ability to work independently while coordinating with multiple technical teams

Preferred:

• Experience supporting taxation or government revenue systems

• Familiarity with CICS and online transaction processing environments

• Experience with data migration or modernization projects involving legacy mainframe applications

• Knowledge of mainframe security, scheduling systems, and source code management tools

• Experience working within largescale enterprise or government IT environments