Senior Software Engineer

Senior Software EngineerConcept Solutions, LLC (CS) is seeking an experienced Senior Software Engineer to join a team responsible for building, modernizing, and sustaining mission-critical applications for a Department of War (DoW) customer.In this role, you will develop, enhance, and maintain high-volume, public-facing applications while supporting secure cloud operations and application modernization. The ideal candidate brings strong backend engineering expertise in Node.js or Go, experience supporting production applications, and a commitment to delivering reliable, secure, and scalable software solutions.Sustain and enhance high-volume, public-facing web applications, resolving defects, applying security patches, and delivering releases under formal change control processes.Develop and maintain backend services using Node.js and Go, with React/TypeScript front-end applications and PostgreSQL databases.Support containerized application deployments in cloud environments.Integrate applications with identity providers and shared platform services to enable secure, seamless functionality.Maintain technical documentation, operational runbooks, and application sustainment procedures.Participate in on-call rotations to support production application availability and incident resolution.Identify and remediate security findings, address vulnerabilities, and maintain current software dependencies.Collaborate with engineering and operations teams to ensure application reliability, performance, and security.7+ years of professional backend software engineering experience, including at least 3 years of production experience with Node.js (JavaScript/TypeScript) or Go (Golang).Strong experience developing and maintaining REST APIs.Hands-on experience with SQL and PostgreSQL databases.Experience operating and supporting production applications in cloud environments.Knowledge of formal change control processes and privileged-access security requirements.Demonstrated ability to troubleshoot production issues, implement fixes, and support application releases.Preferred QualificationsProduction development experience with both Node.js and Go.Experience with React and TypeScript.Familiarity with Amazon ECS or Kubernetes for container orchestration.Experience supporting applications in AWS GovCloud environments.Experience integrating applications with identity providers using OIDC or SAML.Current favorably adjudicated Tier 5 investigation or active Top Secret clearance, enabling immediate privileged access.Work Location and ScheduleLocation: RemoteSchedule: Full-time, 40 hours per week, Monday through Friday, with core hours of 9:00 a.m.–3:00 p.m. Eastern. Work follows two-week Agile sprints, including customer demonstrations each sprint.Travel: 0–10%, within the Washington, DC metropolitan area.Security Requirement: U.S. citizenship is required. This is a privileged-access position. Candidates must hold a current favorably adjudicated Tier 5 investigation or Top Secret clearance or be eligible to obtain one. An active clearance may allow for an earlier start.Compensation: $170,000–$180,000 annually, depending on experience.Company Profile:Founded in 1999 and headquartered in Reston, Virginia, Concept Solutions, LLC (CS) is a leading small business in technology, engineering, and management consulting. We are the innovative and agile force behind strategic solutions that enhance organizational efficiency and safeguard our nation across Aerospace, Defense, and National Security sectors.For over 25 years, CS has been a trusted partner for the Federal Aviation Administration (FAA), Department of Homeland Security (DHS), Department of Justice (DOJ), Department of Defense (DoD) and other federal agencies delivering vital IT, security, and project management services.Our commitment to excellence is reflected in our adherence to CMMI-DEV ML3, ISO 9001:2015, ISO/IEC 20000-1:2018, and ISO/IEC 27001-1:2013 standards. CS boasts company highlights that include:Over two decades of experience across over $300 million in contract awards supporting critical FAA programsMultiple contract vehicles providing opportunities across FAA, DoD, NOAA, and other Federal agenciesInnovation Council - CS maintains an active Internal Research and Development (IR&D) program that is geared towards identifying emerging technologies and pursuing technological innovationsAt CS, we know our success stems from our talented team. That's why we prioritize the wellbeing and growth of our employees, fostering a positive culture centered on innovation, engagement, and career development.Benefits: Concept Solutions offers a competitive benefits and salary package you would receive from a large company. We offer health, dental, vision and life insurance, as well as a comprehensive 401(k) plan with matching and immediate vesting.Concept Solutions is an Equal Opportunity Employer, and we value workplace diversity. We invite resumes from all interested parties and consider applicants for all positions without regard to race, color, religion, sex, national origin, age, marital status, sexual preference, personal appearance, family responsibility, the presence of a non-job-related medical condition or physical disability, matriculation, political affiliation, veteran status, or any other legally protected status. Concept Solutions is a VEVRAA federal contractor, and we request priority referral of veterans for available positions.