Senior Full Stack Software Developer Jobs in California

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 empowering teams to take on the toughest challenges of today and tomorrow. With a culture built on innovation and operational excellence, LLNL is a place where your expertise can make a real impact.
Job Description
Are you energized by the challenge of building robust data management systems that become the backbone of critical scientific work? Do you light up at the intersection of solid software engineering and cutting-edge AI capabilities? We're 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.
You will

• 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.

Additional job responsibilities, at the SES.4 level

• 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.
• Provide remote and on-site SME technical support for various customers. Assist the APL in developing and presenting internal and external funding proposals.
• 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.
• Partner with the APL and senior team leads to propose and shape tactical and strategic directions for N Program projects within Global Security.

Qualifications

• 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.

Additional qualifications at the SES.4 level

• Expert-level experience working effectively from frequently vague highly complex requirements with a variety of technical, non-technical and military personnel.
• Subject matter expert experience developing innovative approaches and applying new technologies to broadly defined tasks and projects.
• Expert-level experience applying effective analytical and problem-solving skills to highly complex problems.

Qualifications We Desire

• 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.

Pay Range
$175,530 - $267,060 Annually
$175,530 - $222,564 Annually for the SES.3 level
$210,630 - $267,060 Annually for the SES.4 level
This is the lowest to highest salary we in good faith believe we would pay for this role at the time of this posting. An employee's position within the salary range will be based on several factors including, but not limited to, specific competencies, relevant education, qualifications, certifications, experience, skills, seniority, geographic location, performance, and business or organizational needs.
Additional Information
#LI-Hybrid
Position Information
This is a Flexible Term appointment, which is for a definite period not to exceed six years.If final candidate is a Career Indefinite employee, Career Indefinite status may be maintained (should funding allow).
Why Lawrence Livermore National Laboratory?

• Included in 2026Best Places to Work by Glassdoor!
• Flexible Benefits Package
• 401(k)
• Relocation Assistance
• Education Reimbursement Program
• Flexible schedules (*depending on project needs)
• Our values - visit https://www.llnl.gov/inclusion/our-values

Security Clearance
This position requires a Department of Energy (DOE) Q-level clearance.If you are selected, wewill initiate a Federal background investigation to determine if youmeet eligibility requirements for access to classified information or matter. Also, all L or Q cleared employees are subject to random drug testing. Q-level clearance requires U.S. citizenship.
Pre-Employment Drug Test
External applicant(s) selected for this position must pass a post-offer, pre-employment drug test. This includes testing for use of marijuana as Federal Law applies to us as a Federal Contractor.
Wireless and Medical Devices
Per the Department of Energy (DOE), Lawrence Livermore National Laboratory must meet certain restrictions with the useand/or possession ofmobile devices in Limited Areas. Depending on your job duties, you may be required to work in a Limited Area whereyou are not permitted to have a personal and/or laboratory mobile devicein your possession. This includes, but not limited to cell phones, tablets, fitness devices, wireless headphones, and other Bluetooth/wireless enabled devices.
Ifyou useamedical device, whichpairs with a mobile device,you must still follow the rules concerningthe mobile device in individual sections within Limited Areas. Sensitive Compartmented Information Facilities requireseparate approval. Hearing aids without wireless capabilities or wireless that has been disabled are allowed in Limited Areas, Secure Space and Transit/Buffer Space within buildings.
How to identify fake job advertisements
Please be aware of recruitment scams where people or entities are misusing the name of Lawrence Livermore National Laboratory (LLNL) to post fake job advertisements. LLNL never extends an offer without a personal interview and will never charge a fee for joining our company. All current job openings are displayed on the Career Page under "Find Your Job" of our website. If you have encountered a job posting or have been approached with a job offer that you suspect may be fraudulent, we strongly recommend you do not respond.
To learn more about recruitment scams: https://www.llnl.gov/sites/www/files/2023-05/LLNL-Job-Fraud-Statement-Updated-4.26.23.pdf
Equal Employment Opportunity
We are an equal opportunity employer that is committed to providing all with a work environment free of discrimination and harassment. All qualified applicants will receive consideration for employment without regard to race, color, religion, marital status, national origin, ancestry, sex, sexual orientation, gender identity, disability, medical condition, pregnancy, protected veteran status, age, citizenship, or any other characteristic protected by applicable laws.
Reasonable Accommodation
Our goal is to create an accessible and inclusive experience for all candidates applying and interviewing at the Laboratory. If you need a reasonable accommodation during the application or the recruiting process, please use our online form to submit a request.
CaliforniaPrivacy Notice
The California Consumer Privacy Act (CCPA) grants privacy rights to all California residents. The law also entitlesjob applicants, employees, and non-employee workers to be notified of what personal information LLNL collects and for what purpose. The Employee Privacy Notice can be accessed here .