Backend Software Engineer

This onsite role in St. Louis offers a competitive salary range of USD 107,900 to 195,050 per year and a benefits package that includes Health and Wellness programs, Income Protection, Paid Leave, and Retirement planning. As a Backend Software Engineer at Leidos, you will design, develop, 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 applications.

Benefits

• Competitive compensation
• Health and Wellness programs
• Income protection
• Paid leave
• Retirement

Responsibilities

• Design, develop, test, and maintain backend services using Java or Python
• Design and implement RESTful APIs to support application functionality and integrations
• Apply solid object-oriented design principles to build scalable, maintainable systems
• Write and optimize SQL queries to support functionality and performance
• Coordinate with external teams to understand data sources, interfaces, and access patterns, translating requirements into backend integrations
• Participate in technical design discussions and contribute to backend architecture decisions
• Develop, deploy, and troubleshoot applications within Linux-based environments
• Diagnose and resolve issues across application and database layers
• Engage in code reviews and uphold engineering standards

Requirements

• Master’s degree with 6–10 years of relevant experience, or Bachelor’s degree in Computer Science, Software Engineering, or a related field with 8–12 years of experience
• U.S. Citizenship
• Active TS/SCI clearance with the ability to pass a Polygraph
• Strong backend experience developing applications in Java or Python
• Proven ability to design and develop RESTful APIs supporting scalable functionality
• Solid SQL experience and ability to optimize queries across relational databases
• Comfort working in Linux 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

Why this role stands out

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