Senior Mainframe Developer (COBOL)
Reston, VA
Experience: 5
Education: BS
Category: Information Technology
Contractor Work Model: Remote
Brand: System One
Compensation Range: 83.33 Per Hour
Job ID: 352233
Date Posted: 06/15/2026
Shortcut: http://jobs.systemone.com/iXa6J7
Senior Mainframe Developer (COBOL)
Location: Primarily Remote
Onsite Expectations: Monthly travel to Reston, VA for PI Planning
Compensation: $83/HR
Employment Type: W2 only
We’re looking for a Senior Mainframe COBOL Developer to support and enhance large-scale enterprise systems. This role is ideal for someone who thrives in a mainframe environment, enjoys solving complex problems, and is open to evolving technologies.
You’ll play a key role in maintaining critical applications, supporting high-volume systems, and contributing to modernization efforts where applicable.
- Primarily remote
- Must live in the DMV area or nearby states (WV, DE, PA) OR be willing to relocate
- Ability to travel to Reston, VA approximately once per month for PI Planning
- Design, develop, test, and maintain mainframe applications using COBOL
- Work across core mainframe tools including CICS, JCL, TSO/ISPF, and related utilities
- Analyze business and technical requirements to develop scalable solutions
- Support production systems, troubleshoot issues, and resolve critical defects
- Perform code reviews, testing, and ensure adherence to quality standards
- Collaborate with cross-functional teams to deliver reliable, high-performing systems
- Participate in Agile ceremonies and PI Planning sessions
- Identify opportunities to improve performance, stability, and maintainability
- Mentor junior developers and contribute to team best practices
Required Experience
- 5–8 years of mainframe development experience
- Strong expertise in:
- COBOL
- CICS
- JCL
- TSO/ISPF
- Mainframe change management tools (e.g., ChangeMan, Topaz)
- Experience supporting large-scale enterprise systems
- Ability to analyze, debug, and work with existing legacy codebases
- Experience in Agile/Scrum environments
- Strong problem-solving and communication skills
- Ability to work independently and as part of a distributed team
- Exposure to Java or modern integration technologies
- Experience with web services (REST/SOA)
- Familiarity with AWS or cloud concepts
- Experience with DevOps / CI-CD pipelines
- Healthcare domain experience (especially working with enrollment or benefits data)
- Experience with Git / Bitbucket
- Bachelor’s degree in Computer Science, IT, or related field
- OR equivalent experience (additional 4 years of relevant work)
System One, and its subsidiaries including Joulé and Mountain Ltd., are leaders in delivering outsourced services and workforce solutions across North America. We help clients get work done more efficiently and economically, without compromising quality. System One not only serves as a valued partner for our clients, but we offer eligible employees health and welfare benefits coverage options including medical, dental, vision, spending accounts, life insurance, voluntary plans, as well as participation in a 401(k) plan.
System One is an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex (including pregnancy, childbirth, or related medical conditions), sexual orientation, gender identity, age, national origin, disability, family care or medical leave status, genetic information, veteran status, marital status, or any other characteristic protected by applicable federal, state, or local law.
#M-1
#LI-AJ1
Ref: #851-Rockville-S1
-
Lead Systems Engineer - AWS Cloud
Reston, VA
Job Title: Lead Systems Engineer - AWS Cloud Location: Reston, VA Type: Contract Rate: 95/hr W-2 Contractor Work Model: Hybrid Hours: 40 hours per week Responsibilities Manage, define, design, and develop system requirements, performing trade-off analy...
Date Posted: 05/26/2026 Recommended
-
Sr. Digital Product Manager
Reston, VA
Job Title: Senior Digital Product Manager Role Type: Contract Pay Rate: $91/hour Role Duration: 1 + year contract – good chance of extensions Location: Reston, VA Work Model: Remote/Hybrid (Must work EST hours) – must easily travel 1X/month onsite Seni...
Date Posted: 06/09/2026 Recommended
-
Network Engineer
Reston , Virginia
Job Title: Network Engineer Location: Reston, VA Role Type: Contract Clearance Required: CI Poly Roles and Responsibilities: Work full-time at the customer site in Reston, VA. Communicate with the customer(s), sales teams, peers, engineering and suppor...
Date Posted: 05/18/2026 Recommended
-
Senior Mainframe Engineer
Merrifield, VA
Job Title: Senior Mainframe Engineer Location: remote Pay rate: open to W2 and established 1099s Position type: multiyear contract We are currently seeking a Senior Mainframe Programmer/Support Analyst with a minimum of 10 years of professional experie...
Date Posted: 05/14/2026 Recommended
-
Full Stack .NET Developer
Pensacola, FL
Full Stack .NET Developer .NET, JavaScript, React, Azure Cloud 10+ yrs of experience Hybrid 3 days a week on-site, Pensacola, FL Hourly Rate: $75-$80/hr. range W2 Multiyear Contract System One has a multi-year contract opening for a senior-level full-s...
Date Posted: 04/02/2026 Recommended
-
Principal Solution Architect - Healthcare
Reston, VA
Job Title: Principal Solution Architect – Healthcare Location: Reston, VA Type: 12 + months contract – strong chance of long-term extensions Contractor Work Model: Hybrid – onsite in Reston 1X per week Overview We are seeking a Principal Solution Archi...
Date Posted: 05/26/2026 Recommended
-
Content Developer
Birmingham, Alabama
Job Title: Content Developer Location: Birmingham, Alabama Type: 6 month Contract Compensation: $25.00 Contractor Work Model: Onsite – onsite Hours: 40.0 Responsibilities Supports the analysis, design, development, implementation, and maintenance of tr...
Date Posted: 04/28/2026 Recommended
-
Software Developer
Washington, District Of Columbia
Title: Software Developer Location: Washington, DC Clearance: Active Secret clearance/Top-Secret preferred Type: Direct Hire Contact: Crystaldinnocenti@systemone.com Successful Software Developer's demonstrate competency in integrating advanced technol...
Date Posted: 03/25/2026 Recommended
-
Java Developer (Secret Clearance)
Arlington, Virginia
Java Developer with OpenFGA experience Arlington, VA - hybrid (2 days a week onsite) Secret clearance is required to start Responsibilities: • Design, develop, and deploy cloud-native and containerized applications using Java and modern cloud technolog...
Date Posted: 06/12/2026 Recommended
-
PL/SQL Developer
REMOTE, Virginia
Job Title: PL/SQL Developer Location: REMOTE, Virginia Responsibilities Develop and maintain Oracle PL/SQL solutions, including functions, procedures, triggers, and packages using Oracle 11g or newer. Participate in production implementations by partne...
Date Posted: 06/15/2026 Recommended
-
.NET Mainframe Developer
Vienna , VA
Job Title: .NET Developer Location: Remote Type: Contract Contractor Work Model: Remote Responsibilities Design, develop, and enhance complex software applications supporting mission-critical, time-sensitive initiatives focused on integrating distribut...
Date Posted: 05/06/2026 Recommended
-
Web Content Developer
Merrifield, VA
Job Title: Web Content Developer Adobe Target Location: Hybrid- Vienna, VA Pay Rate: $48/hr. range W2 Benefits available Position Type: Multiyear Contract Description The Web Content Developer will assist in the development and maintenance of the organ...
Date Posted: 05/18/2026 Recommended
-
Forgerock Developer
Salt Lake City, Utah
Job Title: Forgerock Developer Location: Salt Lake City, Utah Type: Contract To Hire Compensation: $0.00 Contractor Work Model: Onsite – onsite Hours: 40.0 Security Clearance: Not specified Overview Leave placeholder text here for recruiter to input Re...
Date Posted: 04/10/2026 Recommended
-
Forgerock Developer
Salt Lake City, Utah
Job Title: Forgerock Developer Location: Salt Lake City, Utah Type: Contract To Hire Contractor Work Model: Onsite Hours: 40.0 Responsibilities Provide support and maintenance of various systems at the client site in Salt Lake City, UT. Be responsible ...
Date Posted: 06/04/2026 Recommended
-
Business Application Developer
Tampa, FL
Job Title: Business Application Developer Location: Tampa, FL Type: Direct Hire Security Clearance: Must Be Able to Obtain a DoD Secret Security Clearance Job Summary: System One is seeking a Business Application Developer for a full-time/permanent opp...
Date Posted: 04/27/2026 Recommended
-
Full-Stack Developer
mclean, Virginia
Senior Full-Stack Developer (Python / Django / AWS) Location: Remote (EST Preferred) Type: Contract To Hire Contractor Work Model: Remote Responsibilities Work closely with clients, technical leads, and cross-functional teams to design and deliver scal...
Date Posted: 05/21/2026 Recommended
-
ServiceNow Developer
Fort Meade, Maryland
Job Title: ServiceNow Developer Location: Fort Meade, Maryland Type: Contract Contractor Work Model: Onsite – onsite Security Clearance: Must hold an active DoD Secret clearance and obtain Security+ certification within 14 days of hire. Responsibilitie...
Date Posted: 06/09/2026 Recommended
-
ServiceNow Developer Senior
Leesburg, Virginia
Job Title: ServiceNow Developer Senior Location: Leesburg, Virginia Type: Contract Compensation: $70-80/HR W-2 Contractor Work Model: Hybrid – onsite and remote Responsibilities Design, develop, and implement ServiceNow applications, modules, scripts, ...
Date Posted: 04/17/2026 Recommended
-
Lead Kafka Developer
Pittsburgh, PA
Job Title: Lead Kafka Developer – Software Engineer Lead Location: Pittsburgh, PA Type: Contract Compensation: Contractor Work Model: Onsite – onsite Hours: 40.0 Security Clearance: Responsibilities Design and develop Kafka-based streaming architecture...
Date Posted: 05/11/2026 Recommended
-
Oracle Technical Developer
Bellevue, Washington
Job Title: Oracle Technical Developer Type: Contract Compensation: $72 - $90 hourly Hybrid: Bellevue, WA Job Title: Oracle Technical Developer Overview: We are seeking an experienced Oracle Technical Developer for a 12-month contract opportunity. In th...
Date Posted: 04/06/2026 Recommended
-
AEM Developer Architect
Centennial , Colorado
Job Title: AEM Developer Architect Location: Centennial, Colorado, United States Type: Contract To Hire Contractor Work Model: Onsite Hours: 40.0 Responsibilities Lead the design and development of enterprise-grade AEM solutions focusing on modularity,...
Date Posted: 04/03/2026 Recommended
-
Adobe Workfront & Fusion Developer
Pittsburgh, Pennsylvania
Job Title: Adobe Workfront & Fusion Developer Location: Pittsburgh, Pennsylvania Type: Direct Hire Compensation: $0.00 Contractor Work Model: Onsite – onsite Hours: 40.0 Security Clearance: Not specified Overview Responsibilities Configure and maintain...
Date Posted: 06/04/2026 Recommended
-
ForgeRock Developer
Midvale , Utah
Job Title: Forge Rock Developer Location: Salt Lake City, Utah System One is seeking a talented, driven, and experienced ForgeRock Developer with strong Java full stack development expertise and a passion for solving complex business challenges. In thi...
Date Posted: 06/04/2026 Recommended
-
Senior Back End Software Developer
Colorado Springs, Colorado
Senior Back End Software Developer Location: Colorado Springs, Colorado Work Model: Onsite Clearance: Eligible – will be processed for Top Secret eventually If interested reach out directly to kimberly.spicer@systemone.com or text 301-252-8762 Responsi...
Date Posted: 05/01/2026 Recommended
-
IRM GRC ServiceNow Developer Senior
Englewood, Colorado
Job Title: IRM GRC ServiceNow Developer Senior Location: Englewood, CO Type: Contract To Hire Compensation: 130-160K Contractor Work Model: On-site Security Clearance: Clearable for a secret clearance (but don't have to have a current one to start). Du...
Date Posted: 04/29/2026 Recommended
-
Data Developer
Arlington, Virginia
Job Title: Data Analyst/Developer Location: Arlington, Virginia Onsite Must be clearable Overview If interested reach out directly to kimberly.spicer@systemone.com or call/text 301-252-8762 Responsibilities Support the delivery of client solutions usin...
Date Posted: 06/10/2026 Recommended
-
Sr. Java Full Stack Developer
Dallas , Texas
Job Title: Sr. Java Full Stack Developer Location: Dallas, Texas Type: Fulltime Compensation: Not specified Contractor Work Model: Onsite – onsite Responsibilities Lead and mentor a team of developers to deliver high-quality solutions Drive architectur...
Date Posted: 05/06/2026 Recommended
-
C/C++ Software Developer
Bossier City, Louisiana
Job Title: C/C++ Software Developer Location: Bossier City, LA Onsite – onsite Security Clearance: Active secret clearance OR previously held secret clearance preferred, must have ability to obtain interim clearance Responsibilities Collaborate with cr...
Date Posted: 06/10/2026 Recommended
-
Java Mainframe Developer
Vienna , VA
Job Title: Java Developer Location: Remote Type: Contract Responsibilities Design, develop, and enhance complex software applications supporting mission-critical, time-sensitive initiatives focused on integrating distributed applications with the organ...
Date Posted: 05/06/2026 Recommended
-
Nuclear Maintenance & Training Developer
Bellevue, WA
Job Title: Nuclear Maintenance & Training Developer Location: Bellevue, WA Type: Contract Compensation: $37.00-$74.00 Contractor Work Model: Remote – offsite Hours: 40.0 Overview System One is seeking a Nuclear Maintenance & Training Developer for a ye...
Date Posted: 06/15/2026 Recommended