Senior Mainframe Developer; Onsite Job Columbia area,Maryland USA,IT/Tech

Position: Senior Mainframe Developer (Onsite)
Job Title: Senior Mainframe Developer (Onsite)

Location: Columbia, MD

Job Type: Full-Time

Job Description:

We are seeking a highly experienced Senior Mainframe Developer to support large-scale enterprise modernization initiatives focused on transforming legacy Mainframe applications into modern, cloud-ready .NET platforms.
This role requires deep expertise in Mainframe technologies, enterprise modernization, and technical leadership. The ideal candidate will lead Mainframe analysis and modernization activities, collaborate with cross-functional engineering teams, and serve as the primary Mainframe technical lead throughout the modernization lifecycle.
Candidates should have strong experience analyzing complex legacy applications, documenting business rules and system dependencies, supporting AI-assisted modernization efforts, and working closely with client stakeholders and modernization teams.
Experience with automated code conversion tools, modernization factories, and enterprise transformation platforms is highly preferred.

Key Responsibilities:

Analyze, maintain, support, and modernize large-scale Mainframe applications and legacy systems
Work extensively with:
- COBOL
- JCL and PROCs
- CICS
- VSAM
- DB2
- IMS
- BMS Maps
- Batch processing environments
Lead Mainframe modernization discussions, workshops, and technical assessments with client stakeholders
Serve as the primary Mainframe technical lead for modernization activities, dependencies, and integration efforts
Analyze legacy business workflows, system integrations, data structures, and application dependencies
Recommend modernization, migration, remediation, and transformation strategies
Support AI-assisted code conversion, remediation, and modernization workflows
Document business rules, technical processes, data mappings, reconciliation logic, and functional behavior
Collaborate closely with .NET developers, architects, QA teams, Dev Ops engineers, and business analysts
Lead source code inventory analysis, dependency mapping, and system assessment activities
Support functional equivalence validation, reconciliation, testing, and stabilization efforts
Assist with enterprise data migration and synchronization between legacy and modernized systems
Troubleshoot production issues, optimize batch workloads, and support application enhancements
Participate in modernization factory workflows including automated analysis, remediation, and transformation activities
Prepare technical documentation, modernization artifacts, operational runbooks, and system analysis reports
Provide mentorship and technical leadership to modernization teams

Required Qualifications:

15+ years of hands-on experience with enterprise Mainframe applications
Strong expertise with:
- COBOL
- JCL and PROCs
- CICS
- VSAM
- DB2
- IMS
- BMS Maps
- Batch processing systems
Strong understanding of:
- Enterprise Mainframe architectures
- Transaction processing systems
- Batch processing frameworks
- Legacy application workflows
- Enterprise integration patterns
Extensive experience supporting large-scale legacy modernization initiatives
Experience working with automated code analysis tools, transformation pipelines, and modernization accelerators
Strong client-facing communication and stakeholder management skills
Experience serving as a technical lead on modernization programs
Strong understanding of enterprise business processes, data flows, and system dependencies
Exposure to:
- Distributed systems
- APIs and middleware
- Hybrid integration architectures
- Cloud modernization initiatives
Familiarity with AWS and/or Azure environments
Strong troubleshooting, analytical, and problem-solving skills
Ability to lead technical modernization activities independently in fast-paced enterprise environments
Excellent written and verbal communication skills

Preferred Qualifications

Exposure to:
- C#
- .NET / .NET Core
- Java
- Modern distributed application environments
Hands-on experience with:
- transformation
- AI-assisted code conversion
- Automated remediation workflows
- Functional equivalence validation
- Modernization factory delivery models
Experience working in Agile/Scrum delivery environments
Experience supporting government, financial, healthcare, tax, or other large enterprise modernization programs
Experience working with modernization factories, automated conversion tools, and migration accelerators
Familiarity with cloud-native modernization and hybrid cloud integration strategies

Technical Environment:

Mainframe Technologies:

Mainframe
COBOL
JCL and PROCs
CICS
VSAM
IMS
DB2
BMS Maps
Batch Processing Systems

Databases:

DB2
Microsoft SQL Server

Modernization & Integration:

Migration
AI-Assisted Code Conversion
Automated Code Remediation
Functional Equivalence Testing
Enterprise Transformation Platforms
APIs and Middleware
System Integration

Cloud & Infrastructure:

AWS
Azure
Hybrid Cloud Architectures

Delivery & Operations:

Production Support
Technical Analysis
Migration Strategy
Source Code Analysis
Dependency Mapping
System Reconciliation
Technical Leadership