Sr Full Stack .NET Developer
Arlington, Virginia
Experience: 10
Category: Information Technology
Contractor Work Model: Hybrid
Brand: System One
Compensation Range: 90.00 - 100.00 Per Hour
Job ID: 349485
Date Posted: 04/17/2026
Shortcut: http://jobs.systemone.com/jz3z6z
Job Title: Sr Full Stack .NET Developer
Rosslyn, VA - Hybrid, 4 days a week on-site
Type: Contract To Hire
Compensation:$90/hr. to $100/hr. Range, commensurate with experience
Minimum Clearance Required to Start: Secret
System One IT has an immediate contract to hire opening for a Senior Full Stack .NET Developer, Lead w/ REACT to support their client’s growing software development contract with a federal end customer in Rosslyn, VA.
The Senior .NET/React developer will be responsible for designing, implementing, and testing the application while working closely with Government stakeholders and users to enhance current business processes.
**Must have at least a Secret Clearance to be considered for the role**
Responsibilities:
- Serve as a Full Stack .NET Developer, Lead w/ REACT with responsibilities to include:
- Participate in project planning sessions with technical and functional leads, business analysts, and other team members to analyze business requirements and outline the proposed IT solution
- Work with customers to clarify requirements, classify and prioritize user requests, and fix bug requests and operational issues reported by users
- Write, interpret, and analyze technical documentation related to information technology
- Deep understanding of SDLC processes, spanning requirements/issue management, defect tracking, source control, build and test automation, and release management
- Provide recommended software development enhancements or changes in support of existing and projected organizational mission requirements
- Create diagrams representing current application designs, data architecture, and flows
- Develop responsive and accessible user interfaces using React, integrating them with .NET back-end services and APIs
Qualifications:
Required:
- Bachelor’s degree in computer science or related degree
- Active Secret clearance
- 10+ years of experience with .NET framework and customization and development involving programming languages like .NET, ASP.NET, C#, HTML, JavaScript, and jQuery
- 3+ years of experience developing front-end applications with React, including state management (Redux or equivalent), hooks, and reusable component design
- Expertise with Microsoft SQL Server
- Expertise building REST APIs, preferably .NET Web API
- Experience performing requirements analysis using Agile methodologies
- Excellent problem solving and resolution skills
- Experience in Application Security Code Review and/or Application Vulnerability Assessment
- Experience developing 508 compliant, cross-browser compatible user interfaces
- Strong knowledge of Azure DevOps (ADO) and CI/CD pipelines
- Exposure to Agile project management and task tracking tools such as ADO Boards or JIRA
Desired:
- Certifications in Azure, AWS, GCP, or other technologies
- Comfortable with designing user interfaces using CSS / Bootstrap
- Experience with React testing frameworks such as Jest or React Testing Library
- Experience working with other front-end frameworks such as Angular
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- MM1
#LI- MM1
Ref: #851-Rockville-S1
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