Software Engineer III (SE3 - St. Louis, MO)

Epsilon C5I ( a division of Epsilon Systems Solutions, is a 100 percent employee-owned company founded in 1998 with more than 20 locations serving the Department of Defense, Department of Energy, Department of Homeland Security, non-profit and commercial customers. The Dayton division has recently been named as one of only five prime awardees for the 10-year, $4.7 billion NOVASTAR contract supporting the National Air and Space Intelligence Center (NASIC), WPAFB, Ohio. The Dayton division has added over 70 full-time employees in just three years and are making plans now to exceed 100 full-time employees by this time next year. We are looking for talented individuals with a passion to serve their nation as we take on the challenges facing the country from threats around the world. Are you ready?

We're seeking a skilled Full Stack Developer III or DevSecOps Engineer III to join our dynamic team in St. Louis, MO, building secure, scalable, and high-performance applications. The ideal candidate will bring a strong foundation in software development alongside a keen understanding of secure coding practices, automation, and deployment pipelines. Whether you're passionate about writing clean, maintainable code across the frontend and backend, or you're focused on integrating security into CI/CD workflows, infrastructure as code, and cloud-native environments, we value your ability to work collaboratively across development, operations, and security teams. You'll play a key role in driving innovation, ensuring software quality, and embedding security throughout the development lifecycle. Candidates must be able to work independently and as part of a technical team and have effective oral and written communication skills. Successful candidates will have strong problem solving and critical thinking skills. Desire an active TS/SCI clearance. Hybrid and remote work available.


Duties and Responsibilities:

• Maintain and enhance existing systems in the development of new features.
• Deploy new secure systems and networks.
• Conduct post processing and data reduction.
• Apply and follow Scrum framework principles.
• Write analysis reports and develop briefings.
• Work independently and in a team environment.
• Design, develop, and implement web applications to power a national toolset with a large user base.
• Applies fundamental knowledge of operating systems and programming languages.
• Works on well-defined problems and learns under direct supervision.
• Possesses sufficient writing skills to prepare and generate technical reports and other documentation pertinent to the position.
• Produce well-written designed, testable and efficient code that meets technical requirements.
• Ability to work closely with users to troubleshoot code defects and deploy timely fixes.
• Participate in a highly collaborative team environment, contributing to all phases of the development lifecycle.
• Deploy applications on classified and secured networks.
• Deliver projects on time and with attention to quality.

Required Qualifications:

• Bachelor of Science degree in engineering, computer science, or information technology.
• 10 or more years of relevant industry experience.
• Good interpersonal skills and the ability to communicate with all levels of business users and management.
• Must have the ability to work independently and in a self-directed fashion, as well as collaboratively on team projects in an environment of cooperation as dictated by the Scrum Guide and in accordance with Agile Methods.
• Effective written, oral, and presentation skills.
• Ability to interface directly with users when necessary to troubleshoot code defects and deploy timely fixes.
• Taking personal ownership in and the initiative to both research, learn and be mentored in new techniques, processes, or technologies when necessary to accomplish mission goals.
• Possessing exceptional writing skills to prepare any relevant technical documentation and generate both internal and client-facing technical reports along with any additional documentation pertinent to the position.
• Applicants must be willing and able to obtain DoD Top Secret security clearance, with SCI access eligibility.
• Pursuant to the various government contractual requirements, all applicants must be U.S. Citizens.

Desired Qualification:

• Prefer Master of Science in Engineering, computer science, or information technology.
• Certification in CompTIA Security+ (Plus)
• Familiarity with React, NodeJS, Django, Qt, CSS/HTML, Visual Studio, TypeScript/JavaScript, Golang, Go, Angular, Argo Workflow, Apache, and Ansible.
• Familiarity with Kubernetes, Docker, and Mesosphere.
• Experience with Elasticsearch, MongoDB, Oracle, PostgreSQL, and SQL Sever.
• Experience with RHEL and CENTOS.
• Real world experience working in a team that focuses on Design, Development, and the Implementation of web applications to power a national toolset with a large distributed user base.
• Familiarity with MATLAB, python, C, C++, C#, and Java.
• Familiarity with Git, GitHub, Gitlab, Jenkins
• Familiarity with Jira, Kafka, RabbitMQ, SQS
• Fundamental applied knowledge of the interconnectivity of operating systems and programming languages.

ADA Notations:

• Regular communication (listening skills/speaking up in meetings).
• Noise conditions range from very quiet to very noisy.
• Prolonged use of computer (typing/keyboarding).
• Frequently required to sit for long periods of time, stand, and walk.
• Ability to travel by car, air or other means of transportation, if required.

Epsilon Systems Solutions, Inc. is an equal opportunity employer. Qualified candidates will be considered without regard to legally protected characteristics.