Mainframe · COBOL · IMS · DB2 · AWS · Go · Python

Level: Senior (8–12 years)

Senior Mainframe Developer – Legacy Platform & Modernization (COBOL, IMS, DB2, AWS, Go, Python)

Location: Hyderabad - hybrid

Experience: 8–12 years

Tech Stack: Mainframe (COBOL, IMS, DB2, JCL, VSAM, CICS), AWS, Go, Python, AI-Assisted Modernization

Role Overview

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, and support COBOL applications on IBM mainframe (z/OS), including both batch and online (CICS/IMS) programs
- Work hands-on with IMS (DB/DC) and DB2 for mainframe data access, including IMS segment/database design, DB2 schema design, SQL, and performance tuning
- Build and maintain deep functional and technical knowledge of the existing mainframe platform, including business logic embedded in legacy COBOL and JCL code
- Support production mainframe systems: troubleshoot, debug, and resolve incidents across batch and online processing
- Partner with architecture and platform teams to identify and assess realistic opportunities for mainframe modernization and transformation toward cloud-native architectures (AWS, Go, Python)
- Contribute to modernization initiatives such as code and data migration, re-platforming, and API-enablement of legacy mainframe functionality
- Build proof-of-concepts and prototypes in Go and/or Python to validate modernization approaches for specific mainframe components




- Document current-state mainframe architecture, data flows, and business rules to support transformation roadmaps
- Collaborate with architects, data engineers, and DevOps teams on hybrid mainframe-to-cloud integration patterns
- Follow appropriate change management, testing, and compliance practices given the criticality of the systems involved
- Mentor junior mainframe developers and share modernization and transformation best practices

Required Qualifications

- Bachelor's degree in Computer Science, Engineering, or a related field, or equivalent practical experience
- 8–12 years of hands-on mainframe development experience, with deep, current expertise in COBOL
- Strong, hands-on experience with IMS (DB/DC) for hierarchical database design and transaction processing
- Strong, hands-on experience with 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 AWS services (EC2, S3, Lambda, IAM) sufficient to participate credibly in modernization and transformation discussions
- Working proficiency in Go and/or Python, particularly for prototyping modernization approaches and building supporting tooling
- Demonstrated ability to read, reverse-engineer, and clearly document complex legacy COBOL/JCL business logic
- Solid analytical skills to assess mainframe components for transformation feasibility, risk, and complexity
- Experience with mainframe change management and version control tools (e.g., Endevor, ChangeMan) and mainframe testing practices




- Strong debugging and production-support skills for mission-critical mainframe systems
- Excellent communication skills to 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

📌 Senior Mainframe Developer (Hyderabad)
🏢 Simplify AlphaTM
📍 Hyderabad