Software Engineer - Frontend Web Developer with Security Clearance

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 Software Engineer specializing in front-end web development to create accessible, reliable, and user-centered applications that support secure customer missions. As part of the Four Sea Group engineering team, this role will help translate complex mission and user requirements into effective digital experiences.

The engineer will contribute to reliable program delivery by independently developing frontend capabilities, integrating them with backend services, and supporting the routine release of high-quality software in an Agile environment. This position also contributes to Four Sea Group's broader technical capability by applying modern development practices, identifying practical open-source solutions, and collaborating across software, systems, integration, and test teams. The ideal candidate combines strong frontend implementation skills with sound technical judgment, adaptability, and a commitment to building software that is usable, maintainable, accessible, and aligned with customer needs.

Required Qualifications
* Bachelor's degree in Computer Science, Software Engineering, Computer Engineering, or a related technical field, or equivalent practical experience.
* Typically four or more years of relevant software engineering or frontend web development experience.
* Active Top Secret clearance at the time of hire, with the ability to obtain and maintain TS/SCI access with a CI Poly.

* Experience developing and deploying user-facing web applications using modern frontend development tools, techniques, and methods.
* Experience with HTML5, CSS3, responsive design, and CSS frameworks or preprocessors such as LESS, SASS, Bootstrap, Bourbon, or comparable technologies.
* Experience developing JavaScript using modern standards, modular development practices, and established frameworks or libraries.
* Experience developing applications with Angular or React, and/or experience developing Java-based services.
* Experience integrating and consuming RESTful APIs.
* Experience creating functional web layouts from static designs, images, wireframes, or comparable design materials.
* Experience creating views or templates within full-stack frameworks such as Rails, Express, Django, or comparable technologies.
* Experience using Git and Git Hub, Git Lab, or a comparable version-control and collaborative development platform.
* Experience working in an Agile or Lean software development environment and supporting routine delivery of software changes.
* Knowledge of Section 508 requirements and experience developing accessible user interfaces.
* Experience evaluating and applying open-source solutions.
* Ability to independently deliver defined frontend features, troubleshoot implementation issues, and contribute to design decisions.
* Ability to quickly research and learn new programming tools, frameworks, and techniques.
* Strong written and verbal communication skills.
* Ability to work in-person (no virtual or hybrid options available) in Littleton, CO

Preferred Qualifications
* Active TS/SCI with CI Poly
* Experience supporting software development in a secure, government, defense, intelligence, or mission-critical environment.
* Experience with automated testing and continuous integration or continuous deployment practices.
* Experience with Jenkins, Puppet, or comparable build, deployment, or configuration-management…