Senior Principal Software Engineer / Deputy Program Manager - CGSWeb

Epsilon Systems Solutions, Inc; St. Louis (MO); On-site; USD 130,000 - 170,000; Full time

Job summary

Epsilon Systems Solutions, Inc. is seeking a Senior Principal Software Engineer / Deputy Program Manager for the CGSWeb ISR&T project in St. Louis, MO.

The role combines senior technical leadership with program management responsibilities on a DoD/IC-enabled program. Requirements include a Master’s in CS, 15+ years of related experience, strong Java/C++/JavaScript, Web Services, and a TS/SCI clearance. You will mentor teams, coordinate with government customers, and ensure timely,

Qualifications

• Master's degree in Computer Science or related discipline.
• 15+ years of progressively responsible experience in software design, development, test, and evaluation with technical leadership.
• Experience leading multidisciplinary teams on complex programs.
• Hands-on experience with Java, C++, JavaScript, React.js, and Web Services.
• AWS experience with network design, integration, analysis, and operation.
• Experience with SVN and Git version control.
• Windows Server administration and upgrade experience.
• Active TS/SCI clearance; U.S. citizenship required.

Responsibilities

• Design, develop, and implement web applications for a national ISR&T toolset with a large user base.
• Provide senior-level technical leadership for software architecture and development activities.
• Perform systems engineering on front-end and back-end applications.
• Write well-designed, testable, efficient code meeting requirements.
• Lead collaborations with users to troubleshoot defects and deploy fixes.
• Deliver projects on time with emphasis on quality and security.

Skills

Java

C++

JavaScript

React.js

Web Services

Git

SVN

Windows Server

Security+ / IAT 8570.01

Education

Master's degree in Computer Science

Tools

Apache Tomcat

Jenkins

Job description

Senior Principal Software Engineer / Deputy Program Manager - CGSWeb

Job ID: 2026-401
Date Posted: 2026-10-08T00:00:00
Location: St. Louis, Missouri
Minimum Experience: 15 years
Education: Master's Degree

Epsilon Systems C5I (https://www.epsilonsystems.com/c5i) is focused on software development and systems engineering for complex command, control, intelligence, and combat systems and is seeking a Senior Principal Software Engineer / Deputy Program Manager with 15+ years of experience for work in St. Louis, MO supporting an Intelligence, Surveillance, Reconnaissance and Target (ISR&T) web development project. Our engineering efforts provide the warfighter with tools and critical support to operational missions to improve targeting capabilities. This position will serve as a senior technical lead while also supporting program execution, customer engagement, and the overall management of program activities. If you have a passion for excellence in engineering, technical leadership, and mission execution and enjoy working on challenging projects in a fast-paced, team-oriented environment – read on!

Duties and Responsibilities:

• Design, develop, and implement web applications to power a national ISR&T toolset with a large user base.
• Provide senior-level technical leadership and direction for software architecture, design, development, integration, test, and deployment activities.
• Perform systems engineering duties on operational javascript front-end and java backend applications.
• Write well designed, testable and efficient code that meets technical requirements.
• 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 secure classified networks.
• Deliver projects on time and with attention to quality.
• Support the Program Manager in the planning, execution, and oversight of program activities, including technical performance, schedule, staffing, deliverables, and program priorities.
• Serve as a primary program and technical interface with Government customers and key stakeholders, providing status, identifying risks, and coordinating resolution of technical and programmatic issues.
• Provide leadership and direction to technical teams, including establishing priorities, coordinating resources, mentoring engineering staff, and ensuring engineering activities remain aligned with contractual and mission requirements.
• Act on behalf of the Program Manager as required, supporting day-to-day program operations, customer meetings, technical reviews, and coordination across engineering, operations, and program management functions.

Required Qualifications:

• Master's of Science degree in Computer Science or related discipline.
• Fifteen (15+) or more years of progressively responsible experience in Software Design, Development, Test, and Evaluation, including experience providing technical leadership for complex software or systems engineering efforts.
• Demonstrated experience leading multidisciplinary technical teams and coordinating software development activities across complex programs or projects.
• Hands on experience with Java, C++, JavaScript, React.js, Web Services.
• Recent Amazon Web Services experience relevant network experience in the design, integration, analysis, troubleshooting, documenting, programming and operation of computer equipment and networks.
• Experience with modern version control systems (i.e., SVN, Git).
• Experience administering/monitoring Windows Servers (including security requirements) and upgrading operational systems.
• Level II IAT 8570.01 Cert such as Security+.
• Good interpersonal skills and the ability to communicate effectively with Government customers, technical personnel, business users, and senior management.
• Ability to work individually and on team projects in an environment of teamwork and cooperation.
• Effective written, oral, and presentation skills.
• Pursuant to the various government contractual requirements, all applicants must be U.S. Citizens.
• Must have an active TS/SCI security clearance.

Preferred Qualifications:

• Previous experience supporting program management, technical program leadership, or similar responsibilities on DoD or Intelligence Community programs.
• Experience with Apache, Tomcat, and managing java applications.
• Understanding of relational databases (PostgreSQL preferred).
• Knowledge of geospatial systems (MSP, CGS, Openlayers, GeoServer).
• Knowledge of imagery formats (NITF, GeoTIFF).
• Knowledge of Identity Management (GeoAxis).

ADA Notations:

• Regular communication (hearing/speaking).
• 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, walk, and may occasionally lift and move at least 25 pounds.
• 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.

Equal employment opportunity, including veterans and individuals with disabilities.

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