Senior Mainframe Developer - Python

Job Description :

We are seeking an experienced Senior Developer / Lead to drive the conversion of legacy SAS programs running on an IBM z/OS mainframe to modern target languages (Python, SQL, COBOL) as part of a large-scale SAS decoupling initiative.

This is a hands-on technical leadership role combining deep mainframe and SAS expertise with the ability to guide a team through AI-assisted conversion, manual remediation, and production cutover of mission-critical financial services workloads.

Key Responsibilities :

• Lead the analysis, classification, and conversion of SAS programs (Inline SAS and Called SAS) and associated JCLs from the IBM z/OS mainframe to Python, SQL, or COBOL.

• Review and validate AI-generated code conversions produced by the Cosmos AI accelerator platform, ensuring functional accuracy and adherence to coding standards.

• Establish and maintain Python execution within the mainframe Unix System Services (USS) environment, including integration with JCL-triggered batch processes.

• Perform deep-dive analysis of complex SAS programs, including macro logic, PROC SQL, and statistical procedures, to determine the optimal target language and conversion approach.

• Identify and document dependencies between JCLs and SAS programs, including cases where a single SAS program is called by multiple JCLs.

• Flag and appropriately route SAS programs with dependencies on systems also targeted for decommissioning (e.g., TIW), avoiding rework against deprecated targets.

• Design and execute unit testing and output parity validation, comparing converted program output against the original SAS baseline.

• Mentor and provide technical direction to a team of conversion developers; review code, resolve technical blockers, and ensure delivery quality across the conversion factory.

• Collaborate with Thrivent SMEs, data owners, and architecture teams to validate business logic and secure sign-off on converted programs.

• Support production cutover activities, including parallel run validation, defect triage, and go-live readiness assessments.

• Contribute to documentation of conversion patterns, reusable accelerators, and lessons learned to improve factory throughput over time.

Required Skills & Experience:

• 8-12+ years of experience in mainframe development, with strong hands-on expertise in SAS (Base SAS, SAS macros, PROC SQL, DATA step programming).

• Strong working knowledge of IBM z/OS, JCL, and mainframe batch processing concepts.

• Proficiency in Python for data engineering or scripting use cases; experience running Python in a Unix/Linux shell environment (z/OS USS experience strongly preferred).

• Working knowledge of COBOL and SQL, with the ability to evaluate and recommend appropriate target languages based on program complexity and logic patterns.

• Experience with legacy-to-modern code conversion or migration projects, ideally involving AI-assisted or automated code generation tools.

• Strong understanding of data validation and reconciliation methodologies for migration projects (output parity, row-count validation, business-rule testing).

• Demonstrated ability to lead or mentor a technical team in a fast-paced, milestone-driven delivery environment.

• Excellent communication skills, with experience engaging directly with client architects, SMEs, and business stakeholders.

• Experience in financial services or other regulated industries is highly preferred.

Preferred / Nice-to-Have:

• Prior experience with SAS-to-Python or SAS-to-Spark conversion tooling or accelerators.

• Familiarity with cloud data platforms (AWS, Databricks, Snowflake) for downstream modernization context.

• Exposure to DB2 on mainframe and related data access patterns.

• Prior consulting or IT services delivery experience, particularly within large enterprise modernization programs.