Senior Software Engineer Job Littleton area,Colorado USA,Software Development

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

We are seeking a Software Engineer to support the design, development, integration, and deployment of software solutions in a fast‑paced, agile environment. This role will contribute to the development of maintainable, reliable, and scalable software, support integration with backend services and mission systems, and help enable routine delivery of changes as part of an agile software team.

The ideal candidate brings strong software development experience, sound implementation judgment, and the ability to work independently while collaborating effectively across engineering teams to support reliable delivery and mission success.

What you'll do

Design, develop, enhance, and maintain software applications, components, and services.
Translate technical requirements into maintainable, well‑structured software solutions.
Develop and integrate software using modern programming languages and development practices.
Support integration with backend services, APIs, and mission systems.
Participate in agile development activities to support iterative delivery and routine deployment of changes.
Use structured version control and development workflows to support collaboration, code review, and release quality.
Troubleshoot software defects, integration issues, and performance challenges affecting delivery and system behavior.
Research and adopt new tools, techniques, and open‑source solutions as needed to support program goals.
Collaborate with software engineers, systems engineers, testers, and other stakeholders to support successful execution.
Contribute to software quality through disciplined development, testing, documentation, and continuous improvement practices.

Required Qualifications

Bachelor’s degree in Computer Science, Software Engineering, Computer Engineering, or a related technical field, or equivalent practical experience.
6+ years of relevant software engineering or frontend web development experience.
Active TS/SCI clearance
Experience with Java development in production or mission‑driven environments.
Experience with C++ development.
Experience with Angular and/or React in application development environments.
Experience working in Agile software development environments.
Experience using Jira or similar agile work‑tracking tools.
Experience using Git Lab, Jenkins, or equivalent tools to support version control, CI/CD, or collaborative development workflows.
Experience integrating and consuming RESTful APIs or service‑based architectures.
Ability to quickly research and learn new programming tools and techniques.
Strong written and verbal communication skills.

Preferred Qualifications

Experience working in secure, mission‑critical, defense, intelligence, or other high‑consequence technical environments.
Experience supporting full software development lifecycle activities, including design, integration, testing, and deployment.
Experience with CI/CD pipelines, automated testing, and modern Dev Ops practices.
Experience with containerization or deployment technologies such as Docker or Kubernetes.
Experience with service‑oriented or distributed system architectures.
Experience working across multidisciplinary teams, including software, systems, integration, and test.
Experience with SAFe processes or other scaled Agile methodologies.
Experience using open‑source solutions and engaging with open‑source communities.

Salary: The salary range for this role is $–$ per year. The salary range provided is a…