Backend Software Engineer

Backend Software Engineer roles at Leidos in St. Louis, onsite, blend rigorous backend engineering with mission-critical application needs. In this position, you will design, build, and maintain scalable backend services and RESTful APIs using Java or Python in a Linux environment to support high-visibility data analysis and mission-critical workflows. Leidos, a prominent technology and government-focused innovator, offers a compensation range of USD 107,900 to 195,050 per year and operates worldwide with thousands of engineers delivering secure, impactful solutions.

About Leidos: Leidos is an industry and technology leader serving government and commercial customers with smarter, more efficient digital and mission innovations. Headquartered in Reston, Virginia, with 47,000 global employees, Leidos reported annual revenues of approximately $16.7 billion for the fiscal year ended January 3, 2025. For more information, visit www.Leidos.com.

Responsibilities

• Backend Development: Design, develop, test, and maintain backend services using Java or Python
• REST API Development: Design and implement RESTful services to support application functionality and integrations
• Object-Oriented Design: Apply strong object-oriented design principles to build scalable and maintainable systems
• Database Development: Write and optimize SQL queries to support application functionality and performance
• Data Source Integration Coordination: Coordinate with external teams to understand data sources, interfaces, and access patterns, and translate requirements into backend integrations
• System Design Contribution: Participate in technical design discussions and contribute to backend architecture decisions
• Linux Environments: Develop, deploy, and troubleshoot applications within Linux-based environments
• System Troubleshooting: Diagnose and resolve issues across application and database layers
• Code Quality & Best Practices: Participate in code reviews and ensure adherence to engineering standards

Requirements

• Bachelor’s degree in Computer Science, Software Engineering, or a related field with 8–12 years of experience; or Master’s degree with 6–10 years of experience
• U.S. Citizenship
• Active TS/SCI clearance with the ability to successfully pass a Polygraph
• Strong professional experience developing backend applications in Java or Python
• Proven ability to design and develop RESTful APIs that support scalable application functionality
• Solid SQL experience, including writing and optimizing queries across relational databases
• Confident working in Linux‑based environments
• Ability to work independently and drive solutions to moderately complex and complex technical challenges

Technologies

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

Benefits

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

Why this role stands out

• High Impact: Your services power a widely used application that drives real-time decisions
• High Visibility: Collaborate directly with engineering teams and mission stakeholders
• Career Growth: Deepen your expertise in backend architecture, API design, and scalable systems
• Challenging Work: Build and optimize complex backend features