Mainframe Developer

Position: Mainframe Developer (Senior - Security Remediation)

Location: Remote

Duration: 6-12+ Months Contract

Role Overview

We are seeking experienced Senior Mainframe Engineers with deep expertise in legacy banking systems to investigate, understand, and safely remediate security vulnerabilities in productioncritical applications. This role requires strong proficiency in COBOL, CICS, DB2, and z/OS, along with the ability to navigate complex, decadesold financial systems where stability and accuracy are paramount. The ideal candidate will be a handson engineer who can trace vulnerabilities to their root cause, implement secure fixes, and ensure safe deployment without disrupting missioncritical banking operations.

Key Responsibilities

• Investigate and analyze security vulnerabilities within legacy mainframe banking applications.

• Trace issues to their technical root cause and design secure remediation strategies.

• Modify and enhance COBOL, CICS, and DB2 codebases while ensuring production stability.

• Collaborate with security, infrastructure, and application teams to validate fixes.

• Conduct secure coding reviews and enforce mainframe security best practices.

• Provide production support for remediation deployments, ensuring minimal disruption.

• Document remediation steps, secure design patterns, and operational improvements.

• Contribute to strengthening longterm resilience of legacy banking systems.

Required Skills

• Strong expertise in COBOL, JCL, CICS, DB2, z/OS.

• Deep understanding of mainframe application architecture and legacy banking systems.

• Handson experience with secure coding practices in mainframe environments.

• Proven ability to remediate vulnerabilities in productioncritical systems.

• Strong problemsolving skills and ability to work independently in highstakes environments.

Preferred Skills

• Experience with largescale financial or banking applications.

• Familiarity with mainframe modernization initiatives.

• Exposure to secure SDLC practices and vulnerability management frameworks.

• Strong communication skills to bridge security and engineering teams.