Senior Mainframe Developer Jobs in Charleston, SC

Full Stack Developer/ Architect

At B&A, we foster and embrace a distinct set of values that we live by and instill in all aspects of our organization: dedication, commitment, partnership, trust, and recognition. We have incorporated these values into successful delivery for our customers since 1988. B&A believes in ensuring its employees feel deeply connected to B&A, recognizing successes and hard work, and providing continuous opportunities to learn and grow. Our people are entrepreneurial thinkers that combine mindset, vision, and experience to drive value – not only to us as an organization, but to the clients we support. We promote a collaborative culture with our clients, and with each other, as one team working towards a common vision. We’d love for you to join our team!

Job Summary

We are seeking an experienced Senior .NET Systems Architect / Developer to support a federal program operating within a legacy technology environment while supporting ongoing system enhancements and integration efforts. This role focuses on maintaining, enhancing, and stabilizing existing systems while contributing to incremental improvements in system architecture, data integration, and development processes.

The ideal candidate will have strong experience in .NET/C# development, familiarity with legacy systems, and a demonstrated ability to support data movement and integration across multiple platforms. This role will also contribute to improving development and deployment workflows, including supporting environment setup and system interoperability.

Responsibilities

• Support development and maintenance of .NET/C# applications within a legacy system environment using Microsoft Visual Studio.
• Assist with establishing and stabilizing development and production environments, including coordination with stakeholders to address setup, configuration, and deployment challenges.
• Design and implement data movement and integration solutions across diverse platforms (legacy systems, databases, and modern tools).
• Analyze existing systems (including COBOL or mainframe components) and recommend practical enhancements to improve performance, reliability, and maintainability.
• Support data modeling and ETL processes to ensure consistent and reliable data flow.
• Collaborate with federal staff, vendors, and internal teams to support continuity of operations and technical alignment.
• Contribute to system and network architecture discussions, including connectivity and performance considerations.
• Support evaluation and application of modern tools and technologies, where appropriate, to enhance data processing and analytics capabilities.
• Identify opportunities to improve efficiency and scalability within existing system constraints.
• Assist with documentation, knowledge transfer, and system continuity efforts.

Education and Experience

• Bachelor’s degree in Computer Science, Information Systems, Engineering, or equivalent experience.
• 5–8+ years of experience in software development and/or system architecture.

Required Qualifications

• Strong experience with:
  • .NET Framework / .NET Core
  • C# development
  • Microsoft Visual Studio development environments
  • Oracle and/or Microsoft SQL Server (MS SQL)
• Experience with data integration, data movement, or ETL processes.
• Familiarity with legacy systems, including COBOL or mainframe environments.
• Experience troubleshooting and supporting development and deployment environments.
• Understanding of system integration and distributed systems.
• Strong communication and collaboration skills.

Preferred Qualifications

• Experience working in federal or highly regulated environments.
• Familiarity with modern data platforms, including Databricks or similar technologies (desired for future-state capabilities).
• Experience with data modeling and database design.
• Exposure to cloud platforms (Azure, AWS, or similar).
• Basic understanding of network architecture and system connectivity.
• Exposure to AI/ML or advanced analytics tools.

Certifications (Preferred)

• CompTIA Security+ (or equivalent baseline certification)
• CompTIA Network+
• Microsoft Certified: Azure Fundamentals or Azure Solutions Architect
• Databricks Data Engineer Certification (desired)
• ITIL Foundation Certification

Key Attributes

• Strong problem-solving mindset in bridging legacy and modern systems.
• Practical, detail-oriented approach to system stability and incremental improvement.
• Ability to work effectively in structured environments with evolving requirements.
• Collaborative approach across government, contractor, and vendor teams.
• Commitment to documentation, knowledge sharing, and operational continuity.

Security Clearance

• Active Top Secret clearance. Able to obtain TS/SCI.

More About iDox:

Notable Clients

B&A has grown to be a company that is trusted by our clients for exceptional service, innovative solutions, and inspired employees. Our service extends through federal, state, and local Government, the private sector, and higher education. Some of our notable clients include Department of Justice, Department of State, FDA and Army.

Benefits and Programs

B&A is proud to offer full time employees a 100% premium paid medical plan option, which includes coverage for medical, prescription, dental, vision, life insurance, AD&D, disability, Teladoc, and accident insurance. In addition to these benefits, B&A employees enjoy paid time off, tuition assistance, B&A sponsored trainings and certifications, commuter transit benefits (SmartBenefits) for DC Metro full-time employees and a free subscription to a virtual exercise platform (NEOU).

B&A has launched several programs to focus on employee engagement, wellness, and assistance.

These include:

• The B&A Cares program: on-staff registered counselor, 30/60/90-day wellness check ins, personal development, financial management, and stress management seminars, wellness challenges, and more
• A formal mentorship program
• Job shadowing and cross training opportunities
• Brand Ambassador program
• Lifeworks Employee Assistance Program (EAP): engagement through guided wellness and peer recognition. Access to various support resources to include counseling, legal guidance, financial planning, and more
• Monthly virtual events
• B&A Annual Wellness Challenge: #StepWithBnA, #WalkDuringLunchWithBnA, #VolunteeringWithBnA, and #ExerciseDuringLunchWithBnA, and more

At B&A, we place significant importance on improving the communities and lives of citizens across the nation through our involvement, technology expertise, and employees. B&A puts an emphasis on charitable efforts in the Northern Virginia area, including Capital Area Food Bank pantry drives, book donations, Hope for Henry Foundation events, and many more. In recognition of all these efforts, B&A has been named a Companies as Responsive Employers (CARE) award recipient by Northern Virginia Family Services and nominated by the Northern Virginia Chamber of Commerce for Outstanding Corporate Citizenship Award.

EEO

B&A provides equal employment opportunities (EEO) to all employees and applicants for employment without regard to race, color, religion, gender, sexual orientation, gender identity or expression, national origin, age, disability, genetic information, marital status, amnesty, or status as a covered veteran in accordance with applicable federal, state and local laws. B&A complies with applicable state and local laws governing non-discrimination in employment in every location in which the company has facilities. This policy covers conduct occurring at B&A’s offices, and other workplaces (including client sites) and all other locations where B&A is providing services, and to all work-related activities.

EEO is the Law

B&A participates in e-Verify. We provide the Social Security Administration (SSA) and, if necessary, the Department of Homeland Security (DHS) with information from each new employee’s I-9 Form to confirm work authorization.