Leidos is looking for a Mid-Level Backend Software Engineer to design, build, and sustain backend components and RESTful APIs that support mission-critical analytics across multiple locations. This on-site role in St. Louis, MO involves developing data processing solutions within a Linux environment to enable real-time decision-making, contributing to systems used across programs. The position offers a salary range of USD 87,100 to 157,450 per year.
You will collaborate with cross-functional teams to understand data sources, transform data into reliable backend services, and uphold code quality through reviews and documentation efforts.
Responsibilities
- Backend development: design, develop, test, and maintain backend application components using Java or Python
- REST API development: develop and maintain RESTful services to support application functionality and system integrations
- Object-oriented programming: apply object-oriented design principles to build scalable and maintainable systems
- Database development: write and modify SQL queries to support application functionality and data retrieval
- Data source collaboration: collaborate with internal and external teams to understand data sources, formats, and access methods, and support integration into backend systems
- Linux environments: develop and troubleshoot applications within Linux-based environments
- Data processing & business logic: implement backend logic for data transformation, processing, and system workflows
- Bug fixing & enhancements: identify, debug, and resolve application-level defects and performance issues
- Code quality: follow coding standards, participate in code reviews, and support documentation efforts
Requirements
- 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 experience
- US Citizenship
- Active TS/SCI with the ability to successfully pass a Polygraph
- Professional experience developing object-oriented applications in Java or Python
- Hands-on experience building and maintaining RESTful APIs
- Basic to moderate experience with SQL capability, including writing queries and working with relational databases
- Working knowledge of 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: Your work supports a widely used application that drives real-time decision-making
- High Visibility: Collaborate with engineering teams and mission stakeholders across programs
- Career Growth: Build deeper expertise in backend development, API design, and scalable systems
- Challenging Work: Contribute to complex backend features — not routine maintenance tasks
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)
- Exposure to cloud environments (AWS or Azure)
- Experience working in Agile development environments
