Software Developer - Multiple Levels - TS/SCI Poly Required

The Analysis Solutions Business Area at Leidos is seeking Software Developers at multiple experience levels to support a government customer in Reston, VA. Candidates will join a fast-paced, mission-focused team of government and contractor personnel developing innovative software and data-driven solutions. Successful candidates will bring strong technical skills, creativity, attention to detail, and the ability to solve complex problems in dynamic environments. This position is onsite in Reston, VA and requires an active TS/SCI with Polygraph for consideration. Basic Qualifications by level - Mid-Level Software Development Engineer Bachelor’s degree in Computer Science, Information Systems, Systems Engineering, or related field with 4+ years of experience (or Master’s with 2+ years) 2+ years supporting Intelligence Community or DoD environments Experience with software development using Java, Python, JavaScript, or TypeScript Experience with full-stack development, including modern front-end frameworks (React/Angular) and backend services/APIs Familiarity with SQL/NoSQL databases, ETL pipelines, and Docker/containerized environments Exposure to cloud platforms (AWS preferred) and DevOps practices Experience integrating AI/ML or LLM-based capabilities is a plus Senior Software Development Engineer Bachelor’s degree with 8+ years of experience (or Master’s with 6+ ye [... source excerpt omitted ...] and cloud-native/containerized systems Experience developing analytic, simulation, or scenario-based applications Experience integrating AI/ML, LLMs, or RAG-based solutions into production systems Ability to lead development efforts and mentor junior engineers Principal Software Development Engineer / Technical Lead Bachelor’s degree with 12+ years of experience (or Master’s with 10+ years) 3+ years supporting Intelligence Community or DoD missions Deep expertise in full-stack development, system architecture, and cloud-based platforms Experience designing complex analytic systems, simulation platforms, and large-scale data pipelines Strong background in AI/ML, LLM integra [... source excerpt omitted ...] en ability to lead technical strategy, prototype innovative solutions, and guide engineering teams Excellent communication and stakeholder engagement skills For All Levels - Key Responsibilities Design, develop, and maintain mission-focused software applications and data platforms Build and support ETL pipelines, APIs, and data integration workflows Develop web-based tools for analysis, visualization, and decision support Integrate AI/ML and advanced analytics capabilities into applications Collaborate with users and cross-functional teams to deliver scalable solutions Support testing, debugging, optimization, and deployment activities Contribute to technical direction, docum