Mainframe Production Support & Development Expert

Reshma Shaik

Mainframe Developer ***********@*****.*** +1-945-***-****

PROFESSIONAL SUMMARY

Mainframe Developer with 11+ years of experience, including 6+ years in banking and financial services as a developer and 5+ years as mainframe system programmer

Strong hands-on experience with COBOL, JCL, DB2, VSAM, CICS, and SQL across application development, enhancement, troubleshooting, and production support.

Extensive L2/L3 Production Support experience troubleshooting complex application and batch issues, performing incident triage, Root Cause Analysis (RCA), recovery, and permanent-fix implementation.

Strong experience supporting high-volume enterprise batch processing, including job monitoring, dependencies, failures, restarts, reruns, recovery, and SLA-critical processing.

Hands-on experience with enterprise scheduling tools including Control-M, CA-7, ZEKE, and IBM Z Workload Scheduler for workload monitoring, scheduling, dependencies, and batch recovery.

Strong SQL and DB2 experience for data analysis, production troubleshooting, query development, reconciliation, validation, and resolution of data-integrity issues.

Experienced in troubleshooting COBOL ABENDs, JCL failures, DB2/SQL issues, VSAM/file errors, dataset problems, data inconsistencies, and long-running batch jobs.

Experienced in analyzing production performance issues involving CPU utilization, job throughput, DB2 SQL performance, file processing, and long-running batch workloads.

Strong experience supporting production deployments, release validation, rollback/recovery activities, post-production monitoring, and application stability verification.

Worked closely with application development, DBA, infrastructure, scheduling, and upstream/downstream teams during critical production incidents and application recovery.

Hands-on experience with production support and debugging tools including Xpediter, Abend-AID, File-AID, SPUFI, TSO/ISPF, SDSF, Endevor, and ServiceNow.

Experienced in maintaining RCA documentation, production runbooks, recovery procedures, implementation plans, batch job flows, and technical documentation.

TECHNICAL SKILLS

Languages

COBOL, JCL, SQL

Databases

DB2, VSAM (KSDS, ESDS)

Mainframe / Online

IBM z/OS, CICS, MQ

Tools & Utilities

TSO/ISPF, SDSF, CA-7, ITSM, HMC, CA-11, Control-M, ZEKE, Endevor, Changeman, Xpediter, Abend-Aid, File-Aid, File Manager, SPUFI, QMF, DCLGEN, IBM Data Studio, DFSORT, Syncsort, IDCAMS, IEBGENER, REXX, JIRA, ServiceNow

AI Tools

ChatGPT, GitHub Copilot (code analysis, documentation, refactoring support)

EDUCATION

M.C.A (Master of Computer Applications) - RVR & JC College of Engineering, India.

WORK EXPERIENCE

Client: Helena Agri-Enterprises

September -2025- Current

Project Title: Helena Agricultural Data Processing System

Role: Mainframe Developer

Technologies: COBOL, JCL, SQL, DB2, VSAM, IBM z/OS

Tools: TSO/ISPF, SDSF, CA-7, Control-M, Xpediter, Abend-Aid, File-Aid, SPUFI, QMF, Endevor, ServiceNow, JIRA, Syncsort

Project Description: Working on a high-volume data processing system for precision agriculture, enabling data-driven crop optimization and fertilizer recommendations. The application processes soil, crop, and field datasets using COBOL batch programs and DB2 to generate actionable insights for improving agricultural productivity. Designing and maintaining batch workflows using JCL and scheduling tools to ensure timely execution of seasonal and daily processing cycles.

Responsibilities:

Working as a Mainframe Developer with Production Support responsibilities, developing, enhancing, and supporting business-critical applications using COBOL, JCL, DB2, VSAM, and SQL.

Developed and enhanced COBOL batch programs for high-volume agricultural and business data processing, implementing application enhancements, business-rule changes, and production fixes.

Designed, modified, and maintained JCL job streams for end-to-end batch processing, including dataset handling, job dependencies, error handling, and restart/recovery procedures.

Developed and optimized COBOL-DB2 programs using embedded SQL, cursors, joins, subqueries, and host variables, and performed SQL analysis for efficient data retrieval and updates.

Worked with DB2 tables, indexes, SQL queries, and access paths to troubleshoot data issues and improve performance of high-volume batch applications.

Utilized VSAM KSDS/ESDS datasets for application data storage and retrieval and resolved file-processing, file-status, and data-integrity issues.

Provided production support by analyzing COBOL logic, JCL job flows, SQL queries, files, job logs, and application data to troubleshoot batch and application failures.

Analyzed and resolved production issues including S0C7, S0C4, S322, JCL errors, file-status errors, data-related failures, and long-running jobs, using Xpediter, Abend-AID, and application/job logs.

Supported Control-M batch scheduling and monitoring, including job dependencies, failed jobs, reruns, restart/recovery activities, and batch performance issues.

Performed SQL-based data analysis, validation, and reconciliation to identify missing, duplicate, invalid, or inconsistent records and resolve production data issues.

Performed unit testing, integration testing, defect resolution, release/deployment validation, and post-production monitoring, supporting code migration across Development, Test, QA/UAT, and Production environments.

Coordinated with application development, database, infrastructure, and upstream/downstream teams for production incident resolution, root cause analysis, application releases, and permanent fixes; maintained technical specifications, batch job-flow diagrams, implementation procedures, and application runbooks.

Company: Infosys Client: Healthcare Provider/Hospital Network

Jun 2023 – March 2025

Project Title: SMS Invision Patient Billing and Revenue Cycle Enhancement

Role: Mainframe Developer

Technologies: COBOL, JCL, DB2, CICS, VSAM, IBM z/OS

Tools: CA-7, Control-M, Xpediter, Abend-Aid, File-Aid, Endevor, ServiceNow

Project Description: The project involved supporting and enhancing the SMS Invision healthcare application used for patient registration, insurance verification, billing, claims processing, and revenue cycle management. The objective was to improve billing accuracy, automate manual processes, and ensure timely claim submissions to insurance providers.

Responsibilities:

Analyzed healthcare business requirements and developed enhancements to patient billing and insurance claims processing applications using COBOL, JCL, DB2, CICS, and IBM MQ.

Developed and maintained COBOL batch and online programs to support healthcare claims processing, billing, data validation, and application business rules.

Developed and maintained JCL job streams for claims processing, billing cycles, reconciliation, financial reporting, file processing, and other scheduled batch workloads.

Developed COBOL-DB2 programs using embedded SQL, cursors, joins, and host variables to retrieve and update patient, billing, claims, and related application data.

Developed and supported COBOL/CICS online programs for inquiry and maintenance functions, including screen validation, transaction processing, and DB2 integration.

Used REXX with TSO/ISPF to develop automation scripts for dataset management, JCL validation, and production support activities.

Performed unit testing, system integration testing, and supported User Acceptance Testing (UAT) activities.

Collaborated with business analysts, healthcare users, and cross-functional teams to validate requirements and system changes.

Prepared implementation plans, coordinated code migrations, and supported production deployments.

Analyzed DB2 performance issues, optimized SQL queries, and resolved database-related production incidents.

Participated in Agile development processes including sprint planning, daily stand-ups, backlog refinement, and retrospectives.

Company: JP Morgan Client: JP Morgan

Mar 2020 - May 2023

Project Title: Asset Management Services

Role: Mainframe Developer

Technologies: COBOL, JCL, DB2, CICS, REXX

Tools: Changeman, CA-7, Control-M, Xpediter, Abend-Aid, File-Aid, Endevor, ServiceNow

Project Description: Converted the existing two-day dividend and capital-gain calculation/posting process into a one-day process. The change incorporated the load-back process into the day-one nightly cycle before posting dividends and capital gains, reducing processing time and improving revenue opportunity.

Responsibilities:

Developed and modified COBOL programs and copybooks to convert dividend and capital-gain processing from a two-day cycle to a one-day cycle.

Implemented logic changes for dividend and capital-gain calculation dates to align with same-day processing requirements.

Enhanced and integrated the load-back process into the nightly batch cycle for redemptions, exchanges, and cancellations.

CICS: Hands-on experience developing and supporting CICS online applications, BMS maps/MAPSETs, transaction processing, COMMAREA, program control, file handling, CICS-DB2 integration, and debugging.

Created REXX scripts to automate dataset validation, job submission, and log analysis using TSO/ISPF, improving operational efficiency.

Modified JCL to restructure batch job flows and support execution within a single processing window.

Worked with DB2 and VSAM datasets for data retrieval, updates, and validation during batch processing.

Analyzed and resolved production issues and ABENDs for high-volume financial transactions.

Conducted unit testing and supported SIT/UAT to validate changes and ensure data accuracy.

Collaborated with business analysts and cross-functional teams to implement enhancements.

Optimized batch processing performance and validated accurate posting within the same-day cycle.

Company: JP Morgan Client: JP Morgan

Apr 2017 - Feb 2020

Project Title: DDA Application

Role: Mainframe infrastructure Associate.

Technologies: COBOL, JCL

Tools: Endevor, SPUFI, ISPF, HMC, Netcool, RACF, ServiceNow, GDPS, HP, IBM z/OS, CA-7, ITSM, CA-11, ISPF, SDSF, TSO, BMC Tools, Remedy, ZEKE, TWS.

Project Description: The Demand Deposit Account (DDA) system is a core banking application used to manage savings and current accounts, supporting high-volume customer transactions, balance maintenance, interest calculation, EOD posting, account updates, and transaction processing.

Responsibilities:

Provided L2/L3 production and application support for business-critical core banking applications using COBOL, JCL, DB2, VSAM, CICS, and SQL, resolving complex production incidents and ensuring application stability.

Investigated production issues by analyzing COBOL programs, JCL job flows, DB2 SQL using SPUFI/QMF, VSAM datasets, job logs, spool output, and application data, performing root cause analysis and implementing permanent fixes.

Supported high-volume End-of-Day (EOD) batch processing, monitoring critical job execution, dependencies, failed jobs, controlled restarts, output validation, and completion within established SLA processing windows.

Supported enterprise batch scheduling using Control-M, CA-7, and ZEKE, including job dependencies, predecessor/successor relationships, job failures, reruns, holds, and restart/recovery activities.

Developed and executed SQL queries for production troubleshooting, data analysis, reconciliation, data correction, and validation of business-critical application data.

Performed data integrity analysis and reconciliation to identify missing, duplicate, invalid, or inconsistent records and coordinated corrective actions with application and database teams.

Troubleshot application ABENDs, JCL failures, DB2 SQL errors, VSAM/file-status issues, dataset contention, space issues, data inconsistencies, and long-running batch jobs.

Performed Root Cause Analysis (RCA) for recurring and high-priority production incidents and coordinated with development, DBA, infrastructure, scheduling, and upstream/downstream teams to implement permanent solutions.

Participated in SEV-1/SEV-2 major incident bridge calls, performed technical analysis and recovery activities, communicated incident status, supported data corrections, and validated fixes in UAT and Production.

Executed application deployments and online releases across UAT and Production environments using MARS, including implementation, rollback support, post-deployment validation, data verification, and stability monitoring.

Monitored production system health including CPU utilization, SPOOL usage, console/WTOR messages, job throughput, batch performance, and system resources, proactively identifying issues affecting critical processing.

Performed planned and emergency operational activities including IPL support, GDPS failover testing, rolling IPLs, disaster recovery exercises, and application/system readiness validation.

Troubleshot RACF authorization and access issues involving datasets, applications, CICS transactions, and batch jobs and coordinated with security teams for resolution.

Managed application-related started tasks, JCL override libraries, job recovery, release implementation, rollback, and operational recovery activities.

Collaborated with business users, application development, DBA, security, scheduling, and infrastructure teams to perform impact analysis, resolve production issues, coordinate recovery, and maintain deployment and operational runbooks.

Company: IBM Client: FIAT and Chrysler Automobiles (FCA US)

Aug 2014 - Apr 2017

Project Title: FCA

Role: Senior Mainframe Operational Professional

Technologies: COBOL, JCL, DB2

Tools: HMC, Netcool, ServiceNow, GDPS, RACF, HP, IBM z/OS, CA-7, CA-11, TWS, ISPF, SDSF, TSO, BMC Tools, Remedy, ZEKE

Project Description: Worked on a mission-critical mainframe infrastructure and batch processing system supporting automotive finance applications for FCA US on IBM z/OS. The system processed high-volume transactions related to loan servicing, dealer settlements, and financial operations.

Responsibilities:

Provided L2/L3 production and application support for business-critical mainframe applications using COBOL, JCL, DB2, VSAM, CICS, and SQL, including incident triage, root cause analysis, recovery, and permanent fixes.

Monitored and supported end-to-end high-volume batch processing, managing job execution, dependencies, failures, restarts, reruns, and job holds using CA-7 and ZEKE.

Analyzed complex production issues by reviewing COBOL program logic, JCL job streams, DB2 SQL, VSAM datasets, job logs, spool output, and application data to identify root causes.

Wrote and executed SQL queries for production troubleshooting, data analysis, reconciliation, and validation of application data.

Analyzed and resolved application ABENDs, JCL errors, DB2/SQL issues, file-processing failures, space issues, dataset contention, and long-running batch jobs.

Edited and executed JCL using override libraries and performed controlled job restarts while validating job dependencies, datasets, and downstream processing.

Identified production performance bottlenecks by monitoring CPU utilization, SPOOL usage, console buffers, job throughput, and long-running jobs.

Performed planned and unplanned IPL activities, including GDPS-based IPLs and rolling IPLs, and validated application readiness following system restoration.

Supported Disaster Recovery (DR) and failover exercises, validating critical applications, batch workloads, and production readiness.

Performed start, stop, and recycle operations for application-related started tasks and handled WTOR/console messages during production operations.

Supported application deployments and online releases across UAT and Production environments using MARS, including post-deployment validation, rollback/recovery support, and stability monitoring.

Participated in critical production incidents and collaborated with application development, DBA, scheduling, and infrastructure teams to troubleshoot issues, execute recovery actions, and implement permanent solutions.

Maintained RCA documentation, operational procedures, recovery steps, deployment runbooks, and production-support documentation.

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