Senior Mainframe Developer

Simplify Alpha™; Hyderabad; On-site; INR 2,500,000 - 5,000,000; Full time

Job summary

Simplify Alpha™ is seeking a Senior Mainframe Developer to design, develop, and maintain COBOL applications on IBM mainframe (z/OS) while building fluency in AWS, Go, and Python for modernization efforts. You will understand the current platform deeply and help shape future transformation.

You will collaborate with architects, data engineers, and DevOps to enable hybrid mainframe-to-cloud integration and drive initiatives across the modernization agenda with strong debugging and

Qualifications

• Bachelor's degree in Computer Science, Engineering, or related field.
• 8–12 years of hands-on mainframe development experience with COBOL.
• Hands-on IMS (DB/DC) for hierarchical design and processing.
• Hands-on DB2 (z/OS) including SQL, schema, and tuning.
• Experience with JCL, VSAM, CICS, batch/online patterns.
• Knowledge of AWS services for modernization discussions.
• Go and/or Python prototyping for modernization.
• Ability to read and document legacy COBOL/JCL logic.
• Strong analytical skills for transformation feasibility.
• Experience with mainframe change management tools.

Responsibilities

• Design, develop, maintain COBOL apps on IBM mainframe (z/OS).
• Work with IMS and DB2 for data access and performance tuning.
• Understand and document existing mainframe architecture and rules.
• Support production mainframes: troubleshoot and resolve incidents.
• Identify modernization opportunities toward cloud-native architectures (AWS, Go, Python).
• Contribute to migration and API-enablement initiatives.
• Build PoCs in Go/Python to validate approaches.
• Mentor junior developers and share best practices.
• Collaborate with architects and DevOps on hybrid patterns.
• Follow changemanagement, testing, and compliance practices.

Skills

COBOL expertise

IMS (DB/DC) knowledge

DB2 knowledge

Go programming

Python programming

AI-assisted development

Cloud modernization

Debugging and troubleshooting

Communication skills

Education

Bachelor's degree in Computer Science, Engineering, or related field

Tools

JCL

VSAM

CICS

Endevor

ChangeMan

AWS services (EC2, S3, Lambda, IAM)

Go

Python

AI coding tools (Claude Code, Copilot)

File-AID/Abend-AID

Job description

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 the systems 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