About the job
We are looking for a Senior Mainframe Developer with deep, hands-on expertise in COBOL, IMS, and DB2 to support and evolve our core mainframe platform. This role has two parts that carry equal weight: staying hands-on with the mainframe systems that run the business today, and building enough fluency in AWS, Go, and Python to identify and help shape realistic opportunities for modernization and transformation. You will be one of the primary people who understands how the current platform actually works, and you will use that understanding to help the organization move it forward.
Key Responsibilities
Design, develop, maintain, andsupport COBOL applications on IBM mainframe (z/OS), including both batch andonline (CICS/IMS) programs
Work hands-on with IMS (DB/DC)and DB2 for mainframe data access, including IMS segment/database design, DB2schema design, SQL, and performance tuning
Build and maintain deepfunctional and technical knowledge of the existing mainframe platform,including business logic embedded in legacy COBOL and JCL code
Support production mainframesystems: troubleshoot, debug, and resolve incidents across batch and onlineprocessing
Partner with architecture andplatform teams to identify and assess realistic opportunities for mainframemodernization and transformation toward cloud-native architectures (AWS, Go,Python)
Contribute to modernizationinitiatives such as code and data migration, re-platforming, and API-enablementof legacy mainframe functionality
Build proof-of-concepts andprototypes in Go and/or Python to validate modernization approaches forspecific mainframe components
Document current-statemainframe architecture, data flows, and business rules to supporttransformation roadmaps
Collaborate with architects,data engineers, and DevOps teams on hybrid mainframe-to-cloud integrationpatterns
Follow appropriate changemanagement, testing, and compliance practices given the criticality of thesystems involved
Mentor junior mainframe developers and share modernization and transformation best practices
Required Qualifications
Bachelor's degree in ComputerScience, Engineering, or a related field, or equivalent practical experience
8–12 years of hands-onmainframe development experience, with deep, current expertise in COBOL
Strong, hands-on experiencewith IMS (DB/DC) for hierarchical database design and transaction processing
Strong, hands-on experiencewith DB2 for z/OS, including SQL, schema design, and performance tuning
Experience with JCL, VSAM,CICS, and standard mainframe batch/online processing patterns
Working knowledge of core AWSservices (EC2, S3, Lambda, IAM) sufficient to participate credibly inmodernization and transformation discussions
Working proficiency in Goand/or Python, particularly for prototyping modernization approaches andbuilding supporting tooling
Demonstrated ability to read,reverse-engineer, and clearly document complex legacy COBOL/JCL business logic
Strong analytical skills toassess mainframe components for transformation feasibility, risk, andcomplexity
Experience with mainframechange management and version control tools (e.g., Endevor, ChangeMan) andmainframe testing practices
Strong debugging andproduction-support skills for mission-critical mainframe systems
Excellent communication skillsto bridge legacy mainframe teams and modern cloud/engineering teams
AI Knowledge & AI-Assisted Development (Required)
Practical use of AI coding/assistant tools (e.g., Claude Code, GitHub Copilot, Cursor, or similar)to accelerate legacy code comprehension, COBOL/JCL analysis, and documentation of business rules embedded in mainframe code
Able to use AI tools to help identify and scope mainframe modernization and transformation opportunities, such as summarizing program logic, mapping dependencies, and drafting candidate migration approaches
Able to critically review and validate AI-generated code, documentation, and analysis for correctness before relying on it in production systems or transformation decisions
Understanding of secure and compliant AI tool usage, including never entering PHI, member data, or other sensitive information from mainframe systems into prompts or external AI tools
Able to identify where AI-driven automation can improve modernization velocity, such as assisted code translation or test-case generation for legacy validation, and champion adoption within the team
Preferred Qualifications
Experience in the US health insurance or payer domain, particularly mainframe-based claims processing, eligibility, or core administration systems
Exposure to healthcare data standards (X12 EDI, HL7, FHIR)
Prior experience on mainframe-to-cloud modernization or re-platforming initiatives
Experience with mainframe-to-cloud integration or modernization tooling (e.g., AWS Mainframe Modernization, IBM Z and Cloud Modernization Stack, or similar)
Familiarity with additional mainframe tools such as File-AID, Abend-AID, or similar
Relevant certifications: IBM mainframe certifications, AWS Certified Cloud Practitioner, or AWS Certified Solutions Architect