*US Citizenship Required *On-site in Fairfax, Virginia, only Think Tank is a woman-owned small business with more than 27 years of proven success delivering exceptional IT and consulting services to the federal government. We are currently seeking an ideal candidate for the position of Application Developer/Software Engineer (Senior Level |7+ years exp.) to support a high-impact staff augmentation project with Fairfax County, Virginia. This position is conditional upon contract award expected in September / October 2025. Résumé of successful candidate(s) will be included with our proposal. The requirements are as follows: - Software engineer should have strong technical experience in all phases of the software development life-cycle (SDLC) with a demonstrated technical expertise in one or more areas of state-of-the-art software development technology. - Provides activities related to enterprise full life-cycle software development projects. - Able to develop detailed functional and technical requirements for client server and web software applications and conduct detailed analyses and module-level specification development of software requirements. - Must be able to define and implement high performance and highly scalable product/application architectures, and able to lead integration activities for operational, tactical, and strategic systems. - Perform complex programming and analysis for web and mobile applications and ETL processing; define requirements; write program specifications; design, code, test and debug programming assignments, document programs. - May supervise the efforts of other developers in major system development projects; determine and analyze functional requirements; determine proposed solutions information processing requirements; and optimize system performance. - Work task could include total custom development, customization as needed for COTS, development of reports, data conversion and support of legacy applications. • ASP.NET • C# • Python • Java • C/C++ • CSS/JavaScript • SQL & SQL reporting • SQL Server • Visual Studio • GIT • CI/CS/CD • Artificial Intelligence (AI)/Machine Learning (ML) • SharePoint • MS Power Platform • Microsoft Internet Information Server (IIS) • MarkLogic • ORACLE • Oracle APEX All work must comply with all relevant Fairfax County standards. This work may require knowledge of HTML, XHTML, XML, XSLT, .NET Framework, Visual Studio, JavaScript