Senior Full Stack Software Developer

LLNL•Livermore, CA

3d•Hybrid

About The Position

We are seeking a software engineer who shares our excitement for creating elegant, scalable data solutions while pushing the boundaries of what's possible with artificial intelligence. This is your opportunity to work on systems where traditional engineering excellence meets the transformative potential of AI. We are seeking a Senior Full Stack Software Engineer 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 developing a modern data management system based on agentic AI workflows that integrate data models, data processing pipelines, and the 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 requires part-time on-site presence due to the nature of the work. This position will be filled at either the SES.3 or SES.4 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.

Requirements

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 discipline, or an equivalent combination of education and relevant experience.
Advanced experience as a full stack software developer, with contributions to both front-end development (React or Angular frameworks, HTML, CSS, TypeScript, and/or JavaScript) and back-end systems including experience with back-end services using modern Python or Node based frameworks (e.g., API design and integration with databases and external services.)
Advanced skills in object-oriented analysis, design and implementation.
Advanced knowledge of and experience with Python and/or JavaScript/TypeScript.
Experience in deploying applications in a Linux/UNIX environment.
Demonstrated ability to define and implement testing strategies and to lead software quality assurance (SQA) efforts, including unit testing, integration testing, and documentation.
Experience providing technical leadership and mentorship, including guiding other developers, reviewing designs and code, and promoting software engineering best practices.
Ability to work independently on ambiguous or complex problems, exercising sound technical judgment and initiative to develop effective solutions.
Ability to work in a highly interactive software development team.
Proficient written and verbal communication skills, necessary to effectively collaborate in a team environment and present and explain technical information, with the ability to document designs and communicate technical concepts.
Expert-level experience working effectively from frequently vague highly complex requirements with a variety of technical, non-technical and military personnel. (SES.4 level)
Subject matter expert experience developing innovative approaches and applying new technologies to broadly defined tasks and projects. (SES.4 level)
Expert-level experience applying effective analytical and problem-solving skills to highly complex problems. (SES.4 level)

Nice To Haves

Master’s degree computer science, computer engineering, or a related technical field.
Comprehensive knowledge and broad experience with Neo4J or other graph databases including querying, data modeling, and transformation of graph-based data.
Experience integrating software systems with external services, APIs, and messaging infrastructure, including RESTful or GraphQL APIs, message brokers (e.g., Kafka, RabbitMQ, NATS), and event-driven or publish/subscribe architectures.
Experience with Kubernetes for container orchestration, including deploying and managing workloads, and integrating Kubernetes with CI/CD pipelines for automated build, test, and deployment workflows.

Responsibilities

Contribute to the design, development, test, and maintenance of full stack software applications to both front-end user interfaces and back-end services. This includes contributing to the development of front-end applications using modern web frameworks such as React or Angular and the development or back-end services using restful frameworks such as Python (Flask, FastAPI), or Node (Express, Nest, Fastify).
Design, develop, test, and maintain components of a cloud-native data management platform, including: Scalable ingestion pipelines for large scientific datasets into a data lake, Knowledge ingestion and retrieval workflows using vector databases for AI/ML applications, Integration with open-source and commercial data catalog and governance tools (e.g., OpenMetadata)
Refactor existing scripts and prototype code into modular, reusable, and maintainable software components, consolidating functionality where appropriate to improve reliability and extensibility.
Participate in all phases of object-oriented product development, including analysis, design and implementation, with direct interactions with sponsors and other modeling agencies.
Contribute to software quality assurance (SQA) activities, including defining testing approaches, reviewing test coverage, and ensuring compliance with project and organizational requirements.
Collaborate with multidisciplinary teams, including software developers, domain experts, and stakeholders, to gather requirements, participate in review designs, and provide high-quality software solutions to problems of moderate complexity.
Serve as a technical contact for complex software development efforts, providing technical direction and mentoring to junior and mid-level developers.
Perform technical risk assessment and mitigation, identifying potential issues related to architecture, performance, maintainability, or data integrity and proposing effective solutions.
Engage other developers frequently to share relevant knowledge, opinions, and recommendations.
Perform other duties as assigned.
Act as the technical lead for the design and development of new major system capabilities, such as distributed data management, Artificial Intelligence integration, large scale scientific modeling and simulation, etc. (SES.4 level)
Provide remote and on-site SME technical support for various customers. (SES.4 level)
Assist the APL in developing and presenting internal and external funding proposals. (SES.4 level)
Act as the technical lead for multiple systems functional areas with responsibility for requirements vetting, design development and reviews, software implementation, documentation, and testing verification with minimal direction. (SES.4 level)
Partner with the APL and senior team leads to propose and shape tactical and strategic directions for N Program projects within Global Security. (SES.4 level)