Senior Full Stack Simulation Software Engineer

Senior Full Stack Simulation Software Engineer Gradient Marine | San Diego, CA | Hybrid (>50% on site)  Build software that shapes the future of autonomous vehicle operations. Why Gradient Marine  At Gradient Marine you'll work on Virtual Maritime Picture (VMP), a commercial, physics-based digital twin simulation platform, supporting U.S. Navy programs and next-generation autonomous systems. We are building software that allows engineers, operators, and mission planners to design, test, validate, and operate complex systems before they ever enter the field. Join a small, highly technical team where every engineer has visible impact. Influence product architecture alongside company leadership. Build production software used by defense and commercial customers. Work across cloud, simulation, graphics, robotics, AI, and distributed systems. Large defense contractors often separate engineers into narrow specialties. At Gradient Marine, you'll help define product direction, architect systems, work directly with users, and see your software deployed rapidly into operational environments. If you're looking for ownership, technical depth, and meaningful impact, this is the opportunity. The Opportunity  We are looking for a Senior Full Stack Software Engineer who enjoys solving difficult technical problems involving distributed systems, simulation, cloud infrastructure, graphics, networking, and full-stack software development. You will help define the technical roadmap of our core product while building production software deployed to defense and commercial customers. What you’ll be working on:  High-performance simulation system  Modern web applications and intuitive user experiences Cloud-native distributed simulation services  Interactive 3D visualization  Networking infrastructure connecting digital twins, robotics, and external systems Scalable architectures supporting hundreds of concurrent simulations  Responsibilities:  Lead design and implementation of core platform capabilities. Architect scalable software frameworks that support digital twin functions Optimize trade-offs between simulation speed, accuracy, and system resource constraints. Apply physics-based and data-driven modeling techniques. Document findings in a clear, accessible format for both technical and non-technical audiences. Demonstrate a growth mindset, continuously expanding technical and domain-specific skills. Remain current with advancements in digital twin technologies and modeling tools. Collaborate directly with customers and operators to solve real mission problems. Mentor engineers and drive engineering best practices. Participate in code review, technical planning, and long-term product strategy.  What Success Looks like: You enjoy difficult technical problems, move quickly, communicate clearly, and take ownership from concept through deployment. You are energized by building products—not simply maintaining software—and are excited to work in a small business environment where your decisions directly influence the company's future. Technology Stack Basic Qualifications Must be a U.S. Citizen with the ability to obtain and maintain a U.S. DoD Secret Clearance Bachelor's degree in Computer Science, Software Engineering, Computer Engineering, or related STEM field. 7+ years of professional software engineering experience. Strong proficiency in C++, Rust, or Python. Experience with software engineering principles, including object-oriented design, data management, multi-threading/multi-processing, and collaborative source control using Git. Experience designing scalable software architectures. Experience writing software to interface with and process data streams from physical hardware, sensors, or network sources. Development of data visualization and processing tools Preferred Qualifications Masters or PhD in a relevant engineering or computer science discipline. Proficiency developing software solutions for defense applications. Proficiency in software engineering principles, including object-oriented design, data management, multi-threading/multi-processing, and collaborative source control using Git. Experience designing and building CI/CD software delivery pipelines (build, test, and deployment automation) Experience with simulation software development for automotive, aerospace, or maritime domains Experience with front-end development for data visualization. Experience building commercial software products at scale. Cloud architecture and scaled deployment experience Security Requirements U.S. Citizenship required. Ability to obtain and maintain a U.S. Department of War Secret Security Clearance or already have existing Secret or TS clearance