Mid-Level Backend Software Engineer

The Mid-Level Backend Software Engineer role at Leidos is based onsite in St. Louis, MO and centers on designing, building, and maintaining backend components, RESTful APIs, and data processing to support mission-critical analytics across multiple locations.

Responsibilities

• Design, implement, test, and maintain backend components using Java or Python
• Build and sustain RESTful services to enable application features and system integrations
• Apply object-oriented design principles to create scalable, maintainable architectures
• Create and modify SQL queries to support data retrieval and application functionality
• Collaborate with internal and external teams to understand data sources, formats, and access methods, and facilitate their integration into backend workflows
• Develop and troubleshoot software within Linux-based environments
• Implement backend logic for data transformation, processing, and workflow orchestration
• Identify, debug, and fix defects and performance issues in the application
• Adhere to coding standards, participate in code reviews, and contribute to documentation efforts

Requirements

• Educational background: Master’s degree in Computer Science, Software Engineering, or a related field with 2–6 years of experience, or a Bachelor’s degree with 4–8 years of experience
• U.S. Citizenship
• Active TS/SCI security clearance with the ability to pass a polygraph
• Professional experience developing object-oriented applications in Java or Python
• Hands-on experience building and maintaining RESTful APIs
• Working knowledge of SQL and relational databases
• Experience operating in Linux-based environments
• Ability to work independently on defined tasks within established technical frameworks and deliver reliable results

Technologies

• Java
• Python
• SQL
• Linux
• Apache Airflow
• Spring Boot
• Django
• GitLab
• Jenkins
• Docker
• OpenShift
• AWS
• Azure

Benefits

• Health and Wellness programs
• Income Protection
• Paid Leave
• Retirement

Why This Role Stands Out

• High Impact: Contribute to a widely used application that supports real-time decision-making
• High Visibility: Collaborate with engineering teams and mission stakeholders across programs
• Career Growth: Deepen expertise in backend development, API design, and scalable systems
• Challenging Work: Tackle complex backend features rather than routine maintenance

Preferred Qualifications

• Experience with Apache Airflow or similar workflow orchestration technologies
• Experience with Spring Boot, Django, or similar backend frameworks
• Exposure to CI/CD pipelines (GitLab, Jenkins, etc.)
• Familiarity with containerization (Docker, OpenShift)
• Experience with cloud environments (AWS or Azure)
• Experience working in Agile development environments