Senior Mainframe Developer Jobs in USA with Visa Sponsorship
Senior Mainframe Developer roles attract H-1B visa and L-1 sponsorship from large financial institutions, government contractors, and insurance companies. Employers rarely find qualified COBOL and z/OS talent domestically, making sponsorship common for candidates with five or more years of mainframe experience. For detailed occupation requirements, see the O*NET profile.
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Get Access To All JobsWork Schedule
Standard (Mon-Fri)
Environmental Conditions
Office
Job Description
As part of the Thermo Fisher Scientific team, you’ll discover meaningful work that makes a positive impact on a global scale. Join our colleagues in bringing our Mission to life every single day to enable our customers to make the world healthier, cleaner and safer. We provide our global teams with the resources needed to achieve individual career goals while helping to take science a step beyond by developing solutions for some of the world’s toughest challenges, like protecting the environment, making sure our food is safe or helping find cures for cancer.
Position Summary
We are seeking a Senior Mainframe Developer to design, develop, and support critical enterprise applications in a complex mainframe environment. This role requires deep technical expertise in COBOL-based systems, strong problem-solving skills, and the ability to contribute to modernization initiatives, including API enablement and integration with distributed platforms.
This individual will play a key role in ensuring system reliability, driving technical improvements, and partnering with cross-functional teams to deliver high-quality solutions.
Key Responsibilities
- Design, develop, test, and maintain applications using COBOL, CICS, VSAM, and IDMS
- Analyze business requirements and translate them into scalable, maintainable technical solutions
- Support and enhance legacy systems while contributing to modernization and transformation efforts
- Develop and expose APIs and services to enable integration between mainframe and distributed systems
- Participate in production support, including root cause analysis and issue resolution
- Provide on-call support, including weekends and off-hours, as part of a rotation
- Collaborate with Product Managers, Business Analysts, QA, and other engineering teams
- Lead or contribute to code reviews, technical design sessions, and best practice development
- Identify opportunities for process improvement, automation, and performance optimization
- Mentor junior developers and provide technical guidance across the team
- Ensure adherence to security, compliance, and development standards
Required Qualifications
- 7+ years of experience in mainframe application development
-
Strong hands-on experience with:
-
COBOL
- CICS
- VSAM
- IDMS
-
Easytrieve
-
Experience with batch and online processing environments
- Proven experience supporting mission-critical production systems
- Strong debugging, analytical, and problem-solving skills
- Experience working in Agile or Scrum environments
- Excellent communication skills, with the ability to work across technical and business teams
- Willingness to participate in on-call rotation (weekends and off-hours)
Preferred Qualifications
-
Experience with mainframe modernization initiatives
-
API enablement (e.g., REST services, z/OS Connect, etc.)
-
Integration with cloud or distributed platforms
-
Familiarity with DevOps practices and CI/CD pipelines in a mainframe context
- Experience with performance tuning and system optimization
- Exposure to tools such as Endevor, Changeman, or similar
- Experience working in hybrid environments (mainframe + distributed systems)
Work Environment
- Hybrid work model: Onsite at least 3 days per week
- Participation in an on-call rotation, including weekends and off-hours support
What Success Looks Like
- Delivers high-quality, reliable code in a complex legacy environment
- Drives incremental modernization while maintaining system stability
- Acts as a technical leader and trusted partner to stakeholders
- Improves team velocity through better design, automation, and collaboration
Work Schedule
Standard (Mon-Fri)
Environmental Conditions
Office
Job Description
As part of the Thermo Fisher Scientific team, you’ll discover meaningful work that makes a positive impact on a global scale. Join our colleagues in bringing our Mission to life every single day to enable our customers to make the world healthier, cleaner and safer. We provide our global teams with the resources needed to achieve individual career goals while helping to take science a step beyond by developing solutions for some of the world’s toughest challenges, like protecting the environment, making sure our food is safe or helping find cures for cancer.
Position Summary
We are seeking a Senior Mainframe Developer to design, develop, and support critical enterprise applications in a complex mainframe environment. This role requires deep technical expertise in COBOL-based systems, strong problem-solving skills, and the ability to contribute to modernization initiatives, including API enablement and integration with distributed platforms.
This individual will play a key role in ensuring system reliability, driving technical improvements, and partnering with cross-functional teams to deliver high-quality solutions.
Key Responsibilities
- Design, develop, test, and maintain applications using COBOL, CICS, VSAM, and IDMS
- Analyze business requirements and translate them into scalable, maintainable technical solutions
- Support and enhance legacy systems while contributing to modernization and transformation efforts
- Develop and expose APIs and services to enable integration between mainframe and distributed systems
- Participate in production support, including root cause analysis and issue resolution
- Provide on-call support, including weekends and off-hours, as part of a rotation
- Collaborate with Product Managers, Business Analysts, QA, and other engineering teams
- Lead or contribute to code reviews, technical design sessions, and best practice development
- Identify opportunities for process improvement, automation, and performance optimization
- Mentor junior developers and provide technical guidance across the team
- Ensure adherence to security, compliance, and development standards
Required Qualifications
- 7+ years of experience in mainframe application development
-
Strong hands-on experience with:
-
COBOL
- CICS
- VSAM
- IDMS
-
Easytrieve
-
Experience with batch and online processing environments
- Proven experience supporting mission-critical production systems
- Strong debugging, analytical, and problem-solving skills
- Experience working in Agile or Scrum environments
- Excellent communication skills, with the ability to work across technical and business teams
- Willingness to participate in on-call rotation (weekends and off-hours)
Preferred Qualifications
-
Experience with mainframe modernization initiatives
-
API enablement (e.g., REST services, z/OS Connect, etc.)
-
Integration with cloud or distributed platforms
-
Familiarity with DevOps practices and CI/CD pipelines in a mainframe context
- Experience with performance tuning and system optimization
- Exposure to tools such as Endevor, Changeman, or similar
- Experience working in hybrid environments (mainframe + distributed systems)
Work Environment
- Hybrid work model: Onsite at least 3 days per week
- Participation in an on-call rotation, including weekends and off-hours support
What Success Looks Like
- Delivers high-quality, reliable code in a complex legacy environment
- Drives incremental modernization while maintaining system stability
- Acts as a technical leader and trusted partner to stakeholders
- Improves team velocity through better design, automation, and collaboration
See all 10+ Senior Mainframe Developer jobs
Sign up for free to unlock all listings, filter by visa type, and get alerts for new Senior Mainframe Developer roles.
Get Access To All JobsTips for Finding Visa Sponsorship as a Senior Mainframe Developer
Target industries with legacy mainframe infrastructure
Banks, insurance carriers, and federal contractors run the largest mainframe environments and sponsor the most visas for this role. Focus your search on these sectors before approaching tech-first companies, which rarely maintain mainframe systems.
Highlight COBOL and z/OS proficiency explicitly
Employers filing H-1B petitions for mainframe roles must prove specialty occupation status. Listing COBOL, JCL, VSAM, and z/OS prominently on your resume strengthens both your application and your employer's case to USCIS for approval.
Expect employer-initiated sponsorship conversations
Mainframe talent is scarce enough that many employers raise sponsorship proactively rather than screening candidates out. Raise your visa status early in the process so hiring managers can loop in HR and confirm their sponsorship process.
Understand the H-1B cap and cap-exempt options
If you missed the H-1B lottery, certain nonprofit research institutions and government entities are cap-exempt and can file year-round. Some mainframe contractors work directly with these organizations, creating an alternative path to sponsorship.
Browse Migrate Mate for verified sponsoring employers
Not every employer advertising mainframe roles will sponsor visas. Migrate Mate filters job listings to surface companies with confirmed sponsorship history, saving you the time of applying to roles that were never realistic options.
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Find Senior Mainframe Developer JobsFrequently Asked Questions
Is Senior Mainframe Developer considered a specialty occupation for H-1B purposes?
Yes. Senior Mainframe Developer roles consistently qualify as specialty occupations under USCIS guidelines because they require at least a bachelor's degree in computer science, information systems, or a closely related field. The specialized nature of COBOL, z/OS, and enterprise batch processing strengthens the employer's petition. Roles requiring JCL optimization, CICS, or DB2 add further evidence of the theoretical and technical depth USCIS looks for.
What visa types do employers use to sponsor Senior Mainframe Developers?
H-1B is the most common visa for this role, particularly at financial institutions and insurance companies. L-1B is an option if you're transferring from an overseas office of the same employer with specialized mainframe knowledge. TN status covers Canadian and Mexican nationals working as computer systems analysts, which mainframe developer roles can sometimes fall under depending on the job description.
Does my degree need to be specifically in computer science to qualify?
Not necessarily. USCIS accepts degrees in computer science, information systems, mathematics, or engineering as qualifying fields. A degree in a related technical discipline combined with mainframe-specific certifications from IBM can also support eligibility. What matters is that your education and experience demonstrate the theoretical foundation behind your mainframe expertise, not just on-the-job training alone.
How competitive is H-1B sponsorship for mainframe roles compared to other software jobs?
Mainframe developers face less competition for sponsorship than general software engineers because the talent pool is significantly smaller and the skills are harder to source domestically. Employers filing for this role are typically motivated sponsors rather than reluctant ones. USCIS approval rates for mainframe petitions are generally high given the clear specialty occupation argument, though no outcome is guaranteed.
Where can I find Senior Mainframe Developer jobs that actually offer visa sponsorship?
Migrate Mate is built specifically for this. It surfaces Senior Mainframe Developer listings from employers with confirmed visa sponsorship history, so you're not spending time applying to roles that screen out international candidates. The platform is designed for job seekers on visas or looking for sponsorship, which makes the search considerably more targeted than general job boards.
What is the prevailing wage requirement for sponsored Senior Mainframe Developer jobs?
U.S. employers sponsoring a visa must pay at least the prevailing wage, which is what workers in the same role, area, and experience level typically earn. The Department of Labor sets this rate to make sure companies aren't hiring foreign workers simply because they'd accept lower pay than a U.S. worker. It varies by job title, location, and experience. You can look up current prevailing wage rates for any occupation and location using the OFLC Wage Search page.
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