Senior Software Engineer – Mission Applications & Command and Control

About Four Sea Group, Inc. Four Sea Group is a 100% employee-owned technical mission support company based in Denver, Colorado. Founded by an aerospace industry veteran and PhD astrophysicist, we support complex defense, space, software, systems, and mission-focused programs for government and industry partners. What sets FSG apart is the caliber of our people and the way we operate: we are a reputation-driven team of highly skilled engineers and technical experts who are brought in for their depth, judgment, and ability to solve difficult problems. As an employee-owned company, we have built our compensation, benefits, and culture around a simple idea: when the company succeeds, that value should go back to the people doing the work.

About the role Four Sea Group is seeking a Senior Software Engineer to design, develop, integrate, and advance full-stack software capabilities supporting complex command-and-control and mission systems.

This role contributes directly to Four Sea Group’s ability to deliver reliable, secure, and mission-effective software in high-consequence customer environments. The engineer will develop capabilities spanning operating system, platform, infrastructure, and mission-application layers, including software that interfaces with hardware systems, supports mission planning and decision-making, and provides users with intuitive ways to understand and operate within complex dynamic environments.

The ideal candidate brings strong full-stack software engineering experience, deep technical judgment, and demonstrated ability to own significant software capabilities or technical areas. Depending on experience and demonstrated scope, the engineer may lead major application components, define reusable technical approaches, architect complex solutions, guide other engineers, and influence broader system and mission outcomes.

This role requires the ability to make sound technical decisions while considering performance, security, maintainability, project schedule, cost, and mission objectives.

Required Qualifications

• Bachelor’s degree in Computer Science, Software Engineering, Computer Engineering, or a related technical field, or equivalent practical experience.
• Typically 8+ years of relevant software engineering experience, with level determined by demonstrated technical scope, complexity, autonomy, and leadership.
• Active DoD TS/SCI security clearance at the time of application.
• Strong full-stack software engineering experience across application, platform, infrastructure, or supporting system layers.
• Strong experience developing object-oriented software using Java 1.8 or later.
• Experience designing, building, testing, deploying, and sustaining complex software products.
• Experience developing microservice-based, distributed, or service-oriented applications.
• Experience producing software architecture, technical design, or interface documentation.
• Experience developing and integrating software across hardware, software, or external system interfaces.
• Experience working within automated CI/CD environments, including unit testing, integration testing, and automated test frameworks such as Robot Framework, Cucumber, or comparable technologies.
• Experience with modern version-control systems and collaborative software-development workflows.
• Experience working within Agile software-development programs.
• Ability to independently own a major application, subsystem, service, or technical area and determine appropriate technical approaches.
• Ability to troubleshoot and resolve complex software, integration, performance, or production issues.
• Ability to evaluate technical alternatives and make decisions considering mission requirements, technical risk, schedule, cost, security, and maintainability.
• Ability to communicate architecture decisions, technical risks, dependencies, and tradeoffs across software, systems, program, and customer stakeholders.
• Strong written and verbal technical communication skills.

Preferred Qualifications

• Experience developing software that provides command-and-control functionality for physical or hardware systems, including command transmission, acknowledgements, telemetry, status handling, or interface integration.
• Experience developing mission-planning, activity-planning, scheduling, constraint-checking, or decision-support software.
• Experience developing user interfaces that visualize complex or dynamic environments in two or three dimensions.
• Experience with Go and Python.
• Experience with PostgreSQL or comparable relational database technologies.
• Experience with RESTful APIs, JMS, event-driven architectures, or message-based systems.
• Experience developing or operating applications within Red Hat Enterprise Linux 8 or comparable Linux environments.
• Experience deploying applications within AWS, Azure, Google Cloud, or another cloud environment.
• Experience with Docker, Kubernetes, Helm, or comparable containerization and orchestration technologies.
• Experience with PKI, secure-development practices, static-code-analysis tools, or software operating under high-security requirements.
• Experience with Git, Maven, Helm, Harbor, or comparable build, deployment, and artifact-management technologies.
• Experience with JavaScript frameworks such as React, Angular, or Vue.
• Experience defining API schemas, deployment standards, reusable architecture patterns, or common technical approaches.
• Experience with ground systems, command-and-control systems, space systems, or other mission-critical environments.
• Experience troubleshooting production services, analyzing system performance, resolving incidents, or supporting operational recovery.
• Operations and Maintenance experience supporting deployed mission software.
• Experience providing technical guidance, design review, mentorship, or leadership to other engineers.
• Experience defining technical approaches or reusable engineering patterns used beyond an individual component or feature.
• Experience architecting solutions to complex or ambiguous technical problems spanning multiple software or system domains.
• Experience serving as a trusted technical resource for engineering, program, or customer stakeholders.

Salary: The salary range for this role is $140,000-$232,000 per year. The salary range provided is a good faith estimate representative of all experience levels. Four Sea Group, Inc. considers several factors when extending an offer, including but not limited to, the role, function and associated responsibilities, a candidate’s work experience, location, education/training, key skills, and market conditions.

Application Deadline: This position is expected to remain open through November 30, 2026. The company may adjust this deadline based on business needs and will update the posting as appropriate.

Benefits: FSG is 100% ESOP-owned, which means our employees share directly in the company’s growth. We offer competitive compensation, a strong employer-funded retirement plan, generous PTO and flexible time-off options, comprehensive health, dental, vision, life, short-term disability, and long-term disability benefits, plus a generous medical stipend that gives employees more choice and flexibility. Our model is intentionally built to keep more value with employees through salary, retirement, benefits, and ownership. You will work alongside experienced engineers and technical leaders on meaningful defense, space, software, systems, and mission support work, with room to grow as a technical expert, mentor, program contributor, or future leader.

EEO Statement: Four Sea Group is an equal opportunity employer and considers qualified applicants for employment without regard to race, color, sex, sexual orientation, gender identity or expression, religion, national origin, marital or familial status, age, disability, veteran status, military service or application for military service.