Mid-Level Backend Software Engineer

Description If you’ve been building your skills in backend development, object‑oriented programming, and mission‑driven engineering, and you’re ready for work that actually moves the needle, this is the kind of opportunity cleared engineers pursue when they want to grow while making real impact. If you take pride in your craft, enjoy solving meaningful technical problems, and want your work to support a mission with visibility at senior levels, you’ll thrive here. We’re hiring a Backend Software Engineer to support a high‑visibility, data‑driven application used across the organization for analytics and reporting. You’ll help build and maintain core backend services, develop RESTful APIs, support data‑driven functionality, and contribute to ongoing system enhancements within a Linux‑based environment. Your work will directly support system reliability, performance, and data accuracy for mission stakeholders. Our primary development team operates out of Gaithersburg, MD, but we also support onsite engineers in Chantilly, VA, Alexandria, VA; Aurora, CO; St. Louis, MO; and Tucson, AZ, giving top talent multiple paths to join the mission. And while the requisition requirements may seem standard fare, the position is not; as it will join a high performing team that is changing the way digital engineering and mission operations intelligence is enabled for our customer. Why This Role Stands Out High Impact: Your work supports a widely used application that drives real‑time decision‑makingHigh Visibility: Collaborate with engineering teams and mission stakeholders across programsCareer Growth: Build deeper expertise in backend development, API design, and scalable systemsChallenging Work: Contribute to complex backend features — not routine maintenance tasks Essential Responsibilities Backend Development: Design, develop, test, and maintain backend application components using Java or PythonREST API Development: Develop and maintain RESTful services to support application functionality and system integrationsObject-Oriented Programming: Apply object-oriented design principles to build scalable and maintainable systemsDatabase Development: Write and modify SQL queries to support application functionality and data retrievalData Source Collaboration: Collaborate with internal and external teams to understand data sources, formats, and access methods, and support integration into backend systemsLinux Environments: Develop and troubleshoot applications within Linux-based environmentsData Processing & Business Logic: Implement backend logic for data transformation, processing, and system workflowsBug Fixing & Enhancements: Identify, debug, and resolve application-level defects and performance issuesCode Quality: Follow coding standards, participate in code reviews, and support documentation efforts Basic Qualifications Bachelor’s degree in Computer Science, Software Engineering, or a related field with 4–8 years of experience; or a Master’s degree with 2–6 years of experienceUS CitizenshipActive TS/SCI with the ability to successfully pass a PolygraphProfessional experience developing object‑oriented applications in Java or PythonHands‑on experience building and maintaining RESTful APIsBasic to moderate experience with SQL capability, including writing queries and working with relational databasesWorking knowledge of Linux‑based environmentsAbility to work independently on defined tasks within established technical frameworks and deliver reliable results Preferred Qualifications Experience with Apache Airflow or similar workflow orchestration technologiesExperience with Spring Boot, Django, or similar backend frameworksExposure to CI/CD pipelines (GitLab, Jenkins, etc.)Familiarity with containerization (Docker, OpenShift)Exposure to cloud environments (AWS or Azure)Experience working in Agile development environments #MARU If you're looking for comfort, keep scrolling. At Leidos, we outthink, outbuild, and outpace the status quo — because the mission demands it. We're not hiring followers. We're recruiting the on