Application Developer with Security Clearance

Job Title: Application Developer Location: Reston, VA (On-Site) Clearance: TS/SCI with Full Scope Polygraph (Required) Company: Quantum Science Solutions (QSS) Compensation: Open Rate ________________________________________ Position Overview Quantum Science Solutions (QSS) is seeking a cleared and local Application Developer to support a mission-critical federal program in the Reston area. This role involves maintaining existing legacy applications and assisting in the transition to a modernized system architecture that enhances enterprise performance, scalability, and security. The successful candidate will bring strong full-stack and backend development expertise, proficiency in Java, RDBMS support, and a solid understanding of API creation and integration. This position requires hands-on technical problem-solving and close collaboration within Agile teams to deliver high-quality, secure, and reliable solutions. ________________________________________ Key Responsibilities Maintain, enhance, and support legacy applications while facilitating transition to new architecture. Develop and maintain backend services, APIs, and data integrations. Provide RDBMS (Relational Database Management System) support including performance tuning and data modeling. Utilize Java for backend development and support system modernization efforts. Apply strong troubleshooting and problem-solving skills to address issues across all application layers. Collaborate within an Agile/Scrum environment alongside developers, testers, and system engineers. Document technical system architecture and application design. Manage source code using Git (GitHub, GitLab, etc.). ________________________________________ Mandatory Skills Minimum 5 years of experience in Full Stack Development. Minimum 3 years of demonstrated RDBMS support experience. Proven Java development experience. Strong troubleshooting and debugging skills. Demonstrated experience in backend development and API creation. Experience working within an Agile development environment. Ability to document technical system architectures and processes. Proficiency with Git (e.g., GitHub, GitLab). ________________________________________ Preferred Skills Experience with C# and legacy system development. Experience integrating applications with Geographic Information Systems (GIS). ________________________________________ Education B.S. in Computer Science, Computer Engineering, Computer Information Systems, or Computer Systems Engineering or equivalent experience. ________________________________________ Why QSS? At QSS, youre not just filling a role, youre shaping mission-critical solutions that keep our nation secure. We invest in your growth, foster innovation, and reward technical excellence. Benefits include: Competitive compensation with annual performance bonuses Premium Medical, Dental, & Vision coverage Generous PTO plus Federal Holidays 401(k) with company match Opportunities for continuous learning and skill developmentbfb3568a-762b-4989-884b-a9682aa104ca