Professional Resume Template for

Mainframe Developer

Julian D. Sterling

Charlotte, NC

(704) 555-0143

julian.sterling@email.com

linkedin.com/in/julian-sterling | github.com/juliansterling | juliansterling.dev

Professional Summary

Systems-oriented Mainframe Developer with 5 years of experience optimizing and maintaining enterprise-scale transaction processing systems in the financial services sector. Expertise in writing high-performance COBOL and JCL, managing DB2 databases, and configuring CICS online environments. Successfully reduced nightly batch execution times by 28% and modernized mainframe integration endpoints to connect with hybrid cloud REST APIs. Proficient with IBM Developer for z/OS, ChangeMan ZMF, Control-M, and TSO/ISPF.

Work Experience

Mainframe Developer — Apex Financial Technologies

Charlotte, NC | June 2023 – Present

  • Optimized 12 core batch processing jobs written in COBOL and PL/I, reducing nightly runtimes by 34% (saving 2.5 hours of processing time daily).
  • Designed and implemented 8 new RESTful API endpoints using IBM z/OS Connect Enterprise Edition to bridge legacy DB2 database transactions with modern AWS microservices.
  • Resolved CICS transaction latency issues by refactoring database access logic, lowering transaction response times by 18% for 4.2 million daily users.
  • Automated deployment workflows using IBM Dependency Based Build and Git, reducing code release cycle times from 14 days to 4 days.

Associate Mainframe Programmer — Sentinel Insurance Group

Columbia, SC | June 2021 – May 2023

  • Maintained and upgraded 45 legacy JCL routines, reducing execution errors by 22% and eliminating automated job restarts.
  • Collaborated on the migration of an IMS database to DB2, successfully mapping and moving 12 million customer records with zero downtime.
  • Performed regression testing and debugging using Xpediter for 3 major financial system releases, identifying and fixing 85 production-critical bugs.
  • Documented 30 core legacy applications, decreasing developer onboarding ramp-up times by 15%.

Education

Bachelor of Science in Computer Science

Clemson University · Clemson, SC · 2021

Skills

COBOL, JCL, PL/I, CICS, DB2, IMS DB/DC, IBM z/OS, TSO/ISPF, Control-M, ChangeMan ZMF, IBM Developer for z/OS (IDz), z/OS Connect EE, REST APIs, Git, VSAM, SQL

Projects

Mainframe API Modernization

Role: Lead Developer

Tools: z/OS Connect EE, COBOL, DB2, CICS, Git

Developed REST API layers around 15 core mainframe transactions, allowing cloud-native applications to query customer ledger databases in under 85ms.

Batch Run-Time Optimization

Role: Mainframe Programmer

Tools: COBOL, JCL, DB2, Control-M, IBM Application Performance Analyzer

Refactored legacy COBOL search logic and redesigned SQL indexes on 4 large tables, reducing batch execution windows by 4.5 hours and saving $65,000 in monthly CPU usage costs.

Certifications

  • IBM Certified System Programmer - z/OS (2024)
  • IBM Certified Application Developer - COBOL (2022)

Additional information

  • Languages: English (Native)
  • Volunteer Work: Mentored 12 computer science students in legacy systems maintenance during regional university hackathons (2023-present)
  • Availability: 2 weeks notice

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Job Market Insights

Market data and opportunities for

Mainframe Developer

Job Market Insights

$85,000

-

$140,000

Avg:

$110,000

Growth Outlook:

The demand for Mainframe Developers in the United States remains resilient, driven by legacy system modernization in the financial services, insurance, and government sectors. Rather than replacing mainframes completely, enterprises are prioritizing hybrid cloud environments, which requires developers who can connect traditional z/OS applications to cloud APIs. The job market is characterized by steady opportunities as a significant portion of the senior workforce reaches retirement age, creating a strong demand for skilled professionals who understand both legacy architectures and modern DevOps pipelines.

Steady demand driven by modernization & retirement cliff

Key Skills Required

Focus on these skills when customizing your resume for recruiter screenings.

Proficiency in mainframe technologies including COBOL, JCL, DB2, and CICS || Experience with mainframe modernization tools like z/OS Connect EE or integrating mainframe systems with REST APIs || Knowledge of legacy systems debugging (e.g., Xpediter, IBM APA) and source control systems (e.g., ChangeMan ZMF, Git)

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FAQ

Common questions about the

Mainframe Developer

position

Are mainframes still relevant in the technology sector?
What is mainframe modernization?
What are the most critical programming languages for a Mainframe Developer?
How has DevOps changed mainframe development?
Do I need to know cloud computing to work as a Mainframe Developer?
What is the difference between batch and online processing on mainframes?
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