Software Developer - Mid Career

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.

The Conflict Simulation Laboratory (CSL) of the Global Security Computing Applications Division (GS‑CAD) within the Computing Directorate is hiring a Senior Software Developer. The role involves analysis, design, development, and implementation of scientific software for the CSL, including the Joint Conflict and Tactical Simulation (JCATS) and JCATS Low Overhead Driver (JLOD) simulation suites. The candidate will work closely with external partners to enable interoperability with other simulation models and tools in a federated environment, supporting advanced training for military and civilian users worldwide.

• Conduct technical tasks and guide the development of object‑oriented software packages using C++ in a Linux environment.
• Interface directly with sponsors, customers, and stakeholders on cross‑organizational coordination.
• Participate in all phases of product development—analysis, design, and implementation—while interacting with sponsors and other modeling agencies.
• Create clear user documentation for new and existing products and keep it updated for enhancements and bug fixes.
• Provide direct technical support to customers and collaborate with JCATS exercise operations support personnel.
• Contribute to field development and integration with external models.
• Travel domestically and/or internationally as needed.
• Support production releases of desktop applications used by customers worldwide.
• Engage other developers frequently to share knowledge, opinions, and recommendations.
• Perform other duties as assigned.

• Act as the technical lead for new major CSL simulation capabilities (e.g., hypersonic weapons, AI integration, directed energy weapons).
• Provide remote and on‑site SME technical support for customers and assist in developing and presenting funding proposals.
• Lead multiple simulation model functional areas, overseeing requirements vetting, design development, reviews, implementation, documentation, and testing verification with minimal direction.
• Partner with the CSL APL and senior team leads to shape tactical and strategic directions for the CSL.

• Ability to secure and maintain a U.S. DOE Q‑level security clearance (U.S. citizenship required).
• Bachelor’s degree in Computer Science, Engineering, Mathematics or a related field, or equivalent experience.
• Advanced knowledge of C++, Python, and/or modern web development technologies.
• Advanced skills in object‑oriented analysis, design, and implementation.
• Experience developing applications in a Linux/UNIX environment.
• Ability to work in a highly interactive software development team.
• Effective interpersonal skills for interaction with all levels of personnel.
• Proficient verbal and written communication skills for collaboration and technical explanation.
• Ability to travel domestically and internationally as needed.

• Expert-level experience handling vague, highly complex requirements with cross‑disciplinary stakeholders.
• Subject‑matter expert experience developing innovative approaches and applying new technologies to broadly defined tasks.
• Expert-level problem‑solving skills for highly complex problems.

• Master's degree in Computer Science, Engineering, or Mathematics.
• Knowledge of event‑based software simulations.
• Experience developing complex client/server software suites.
• Experience developing object‑oriented GUIs, including OpenGL.
• Knowledge of plane and solid geometry and vector analysis.
• Knowledge of domestic and foreign military operations.

$175,530 – $267,060 Annually (SES 3: $175,530 – $222,564; SES 4: $210,630 – $267,060). Pay is based on competency, education, experience, seniority, location, performance, and business needs.

This is a Flexible Term appointment, limited to a maximum of six years. If the final…