Software Engineer

CONCEPT SOLUTIONS LLC•Reston, VA

16d•$130,000 - $150,000•Remote

About The Position

Concept Solutions, LLC is seeking a Software Engineer to support a mission-critical application modernization program for a Department of War customer. The position is contingent upon contract award, with an anticipated start in October 2026. The program aims to create a unified experience across multiple production applications through single sign-on, a common work surface, and a scalable approach to integrating applications into a shared platform. The Software Engineer will maintain and support existing Java applications, ensuring stability, reliability, and continuity during modernization. The role includes troubleshooting defects in Java Spring Boot applications, developing patches according to the customer's release schedule, supporting the transition to a modernized platform, and keeping a legacy application stable through its planned retirement without adding enhancements. The engineer will also document legacy application capabilities to support the successor system and review, understand, and safely modify unfamiliar codebases. This is a remote, full-time role for 40 hours per week, Monday through Friday, with core hours from 9:00 a.m. to 3:00 p.m. Eastern. Work follows two-week sprints, including a customer demonstration each sprint. Travel is 0–10% within the Washington, DC metropolitan area. U.S. citizenship is required, and the candidate must be eligible to obtain and maintain a DoD security clearance; the requirements section specifies an active Secret clearance. Compensation is a base salary of $130,000–$150,000, depending on experience.

Requirements

At least 3 years of experience working with Java, Spring Boot, and SQL.
Demonstrated ability to understand, troubleshoot, and safely modify existing application code.
Active Secret security clearance.
U.S. citizenship.
Must be eligible to obtain and maintain a DoD security clearance.

Nice To Haves

Experience with Amazon ECS/Fargate and AWS GovCloud.

Responsibilities

Troubleshoot and resolve defects in Java Spring Boot applications.
Develop and implement patches in accordance with the customer's established release schedule.
Maintain existing applications while supporting the transition to a modernized platform.
Ensure the stability of a legacy application through its planned retirement without introducing enhancements.
Document legacy application capabilities to support the successor system.
Review, understand, and safely modify unfamiliar codebases.