Senior Mainframe Developer

Citi; Jacksonville (TX); On-site; USD 114,000 - 171,000; Full time

Benefits offered by this job

Medical, dental & vision coverage

401(k)

Paid time off

Job summary

Citi in Jacksonville, FL is seeking a Senior Mainframe Developer to lead applications development initiatives within the Technology group. You will drive analysis, programming, and implementation of new and revised systems, partnering with multiple teams to deploy enhancements.

The role requires 5+ years of IBM mainframe development, Cobol batch/online expertise, and strong knowledge of mainframe tools. Leadership and strong communication are essential for steering complex projects.

Qualifications

• 5+ years in IBM mainframe development.
• Experience developing batch and online Cobol programs.
• Experience with IBM mainframe tools and data structures (Fileaid, Rexx, JCL, CICS, Changeman, Github, Expediter, TSO/ISPF, VSAM, DB2).
• 2+ years using AI tools such as Devin AI and CoPilot.

Responsibilities

• Partner with management teams to integrate functions and define system enhancements.
• Resolve high-impact problems through evaluation of business processes and standards.
• Provide expertise in applications programming and ensure design follows architecture blueprint.
• Develop standards for coding, testing, debugging, and implementation.
• Analyze how areas like architecture and infrastructure integrate to meet goals.
• Provide in-depth analysis to define issues and develop innovative solutions.
• Mentor mid-level developers and analysts, allocating work as needed.
• Assess risk and ensure compliance with laws, rules, and Citi policies.

Skills

IBM mainframe

Cobol batch/online

Mainframe tools

AI tools (Devin AI, CoPilot)

System analysis

Leadership/PM

Communication

Education

Bachelor’s degree

Master’s degree preferred

Tools

Fileaid

Rexx

JCL

CICS

Changeman

Github

Expediter

TSO/ISPF

VSAM

DB2

Job description

The Senior Mainframe Developer is a senior level position responsible for establishing and implementing new or revised application systems and programs in coordination with the Technology team. The overall objective of this role is to lead applications systems analysis and programming activities.

Responsibilities:

• Partner with multiple management teams to ensure appropriate integration of functions to meet goals as well as identify and define necessary system enhancements to deploy new products and process improvements

• Resolve variety of high impact problems/projects through in-depth evaluation of complex business processes, system processes, and industry standards

• Provide expertise in area and advanced knowledge of applications programming and ensure application design adheres to the overall architecture blueprint

• Utilize advanced knowledge of system flow and develop standards for coding, testing, debugging, and implementation

• Develop comprehensive knowledge of how areas of business, such as architecture and infrastructure, integrate to accomplish business goals

• Provide in-depth analysis with interpretive thinking to define issues and develop innovative solutions

• Serve as advisor or coach to mid-level developers and analysts, allocating work as necessary

• Appropriately assess risk when business decisions are made, demonstrating particular consideration for the firm’s reputation and safeguarding Citigroup, its clients and assets, by driving compliance with applicable laws, rules and regulations, adhering to Policy, applying sound ethical judgment regarding personal behavior, conduct and business practices, and escalating, managing and reporting control issues with transparency.

Recommended Qualifications:

• 5 + years in IBM mainframe development.

• Need experience with developing batch and online programs in Cobol.

• Experience with IBM utilities and other mainframe tools and data structures such as Fileaid, Rexx, JCL, CICS, Changeman, Github, Expediter, TSO/ISPF, VSAM, DB2

• 2+ years experience using AI tools such as Devin AI and CoPilot.

• Extensive experience system analysis and in programming of software applications

• Experience in managing and implementing successful projects

• Subject Matter Expert (SME) in at least one area of Applications Development

• Ability to adjust priorities quickly as circumstances dictate

• Demonstrated leadership and project management skills

• Consistently demonstrates clear and concise written and verbal communication

Education:

• Bachelor’s degree/University degree or equivalent experience

• Master’s degree preferred

This job description provides a high-level review of the types of work performed. Other job-related duties may be assigned as required.

Job Family Group:

Technology

Job Family:

Applications Development

Time Type:

Full time

Primary Location:

Jacksonville Florida United States

Primary Location Full Time Salary Range:

$113,840.00 - $170,760.00

In addition to salary, Citi’s offerings may also include, for eligible employees, discretionary and formulaic incentive and retention awards. Citi offers competitive employee benefits, including: medical, dental & vision coverage; 401(k); life, accident, and disability insurance; and wellness programs. Citi also offers paid time off packages, including planned time off (vacation), unplanned time off (sick leave), and paid holidays. For additional information regarding Citi employee benefits, please visit citibenefits.com. Available offerings may vary by jurisdiction, job level, and date of hire.

Anticipated Posting Close Date:

Jun 15, 2026

Citi is an equal opportunity employer, and qualified candidates will receive consideration without regard to their race, color, religion, sex, sexual orientation, gender identity, national origin, disability, status as a protected veteran, or any other characteristic protected by law.

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