Full Stack Software Developer

Company Description

Join us and make YOUR mark on the World! Lawrence Livermore National Laboratory (LLNL) has turned bold ideas into world‑changing impact, advancing science and technology to strengthen U.S. security and promote global stability. Our mission spans four critical national security areas: nuclear deterrence, threat preparedness, energy security, and multi‑domain defense. With a culture built on innovation and operational excellence, LLNL is a place where your expertise can make a real impact.

Are you looking for ways to spend less time on repetitive tasks? Help us explore how GenAI can enhance and streamline nuclear facility operations. We are seeking a Full Stack Software Developer to design, develop, and maintain complex software systems supporting mission‑critical analytical and operational workflows. You will contribute across the full technology stack, from modern web‑based user interfaces to back‑end services, data pipelines, and software quality assurance processes.

This role requires close collaboration with scientists, engineers, and domain experts to translate complex requirements into robust, maintainable, and scalable software solutions. The work involves graph‑based data models, document processing pipelines, version control and change management, and integration of advanced AI‑enabled tooling. This position is within the Global Security Computing Applications Division (GS‑CAD) of the Computing Directorate, matrixed to the Global Security Directorate.

This position will be filled at either level based on knowledge and related experience as assessed by the hiring team. Additional job responsibilities (outlined below) will be assigned if hired at the higher level.

• Contribute to the design, development, test, and maintenance of full‑stack software applications for both front‑end user interfaces and back‑end services. This includes developing front‑end applications using modern JavaScript frameworks such as React or Angular, and implementing and maintaining back‑end services using Flask.
• Utilize Neo4J graph databases extensively, including:
  • Querying, extracting, and transforming graph nodes and relationships
  • Aggregating nodes and calculating derived values from graph‑based data
  • Rendering graph‑based data in alternative visual or structured representations to support analytical workflows
• Support and enhance version control and change management workflows, including:
  • Tracking changes across evolving data and document versions
  • Implementing mechanisms for diffing and comparing new document versions based on encoded graph structures
• Refactor existing scripts and prototype code into modular, reusable, and maintainable software components, consolidating functionality where appropriate to improve reliability and extensibility.
• Develop unit tests and supporting artifacts to ensure software quality, reliability, and maintainability according to SQA documentation in accordance with project and organizational standards.
• Collaborate with multidisciplinary teams, including software developers, domain experts, and stakeholders, to gather requirements, participate in review designs, and deliver high‑quality software solutions to problems of moderate complexity.
• Apply best practices in software engineering, including code reviews, documentation, configuration management, and secure development practices.
• Perform other duties as assigned.

• Serve as a technical contact for complex software development efforts, providing technical direction and mentoring to junior and mid‑level developers.
• Contribute to SQA activities, including defining testing approaches, reviewing test coverage, and ensuring compliance with project and organizational requirements.
• Perform technical risk assessment and mitigation, identifying potential issues related to architecture, performance, maintainability, or data integrity and proposing effective solutions.

• Ability to secure and maintain a U.S. DOE Q‑level security clearance, which requires U.S. citizenship.
• Bachelor’s degree in computer science, software engineering, or a related technical…