Senior Full Stack Developer
About The Position
Leidos is seeking a Senior Full Stack Developer / Senior Software Engineer to guide technical support, development, and expansion of its core application ecosystem. The role takes hands-on ownership of applications built with React.js, Node.js, Python, and PostgreSQL. Initial work includes directly transitioning existing internal tools and core applications into the supported ecosystem without complex migration planning. As a senior team member, this position supports and scales active applications, designs new features, and collaborates with technology experts to build new software applications. It also supports integration of AI-driven tools, chat interfaces, workflows, and data pipelines. The role operates in a highly collaborative, fast-moving small-team environment and includes technical leadership, application maintenance, troubleshooting, code quality, testing, and mentorship of a Mid-Level developer.
Requirements
- Active TS/SCI with Polygraph.
- Bachelor’s degree and 12–15 years of relevant experience, or a master’s degree and 10–13 years of relevant experience; may possess a doctorate in a technical domain.
- Develops highly innovative solutions through research and integration of best practices.
- Recommends and develops technical solutions, products, and/or standards supporting program strategy and operations.
- Strong experience building production-grade web applications using React.js and Node.js in JavaScript/TypeScript ecosystems.
- Strong Python experience for backend services, background jobs, or data-processing pipelines, and deep knowledge of robust RESTful APIs, specifically with frameworks such as FastAPI.
- Strong PostgreSQL or similar relational database skills, including schema design, indexing, complex joins, and query optimization.
- Comfort reading and understanding legacy C#/.NET structures to guide application transitions; writing or maintaining C# is not required.
- Deep familiarity with Git and CI/CD concepts.
Nice To Haves
- Practical experience working in an Agile development environment such as Scrum, Kanban, or similar sprint-based workflows.
- Practical experience or familiarity supporting AI-adjacent application features, such as conversational/chat interfaces, vector databases, or Retrieval-Augmented Generation (RAG) architectures.
- Experience with Docker configurations, container security, or image hardening; containerization is not a strict requirement.
- Thrives in a small team with high autonomy, direct business impact, and less corporate red tape.
- Eager to brainstorm with technical experts to build new platforms and solve new problems from the ground up.
- Focused on shipping clean, working software on time rather than over-engineering complex frameworks.
Responsibilities
- Act as a core technical lead for active web applications, taking responsibility for system health, code quality, and technical design.
- Oversee day-to-day application maintenance, troubleshooting, and operational support to ensure reliability.
- Manage the direct transition of core tools into the supported ecosystem with minimal friction.
- Architect and build features and new applications; optimize Python backend processing scripts, scale Node.js services, and design high-performance APIs using FastAPI or RESTful approaches.
- Assist with development and technical integration of emerging features, including chat interfaces, RAG concepts, and intelligent application components.
- Conduct code reviews, establish testing strategies, and mentor a Mid-Level developer.
- Set up and maintain foundational repositories, boilerplates, and clean code standards for the React/Node/Python stack.
- Perform programming, documentation, configuration management, testing, and bug fixing across the software release life cycle.
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What This Job Offers
Job Type
Full-time
Career Level
Senior
