Full Stack Web Development Intern Jobs in Saint Louis, MO

Are you ready to build software that makes a real‑world impact? Leidos is seeking a talented Mid-Level Full Stack Software Engineer to join the Chinook Program supporting an Intelligence Community customer. In this role, you’ll design, develop, and deliver modern software solutions that enable critical national security missions while working alongside some of the industry’s brightest engineers, architects, and mission experts.

As a Full Stack Engineer, you’ll contribute across the entire software development lifecycle, from crafting intuitive user interfaces to building scalable backend services and integrating secure, cloud‑native solutions. Working within a collaborative Agile environment, you’ll help deliver high-quality capabilities through iterative development, continuous integration, and DevSecOps best practices.

In this role, you will work on cross-functional development teams to build and maintain microservices, APIs, and web-based applications that support GEOINT data access, visualization, and dissemination. You will contribute to the full software lifecycle and will have the opportunity to work directly with users, cloud engineers, and mission stakeholders.

If you’re passionate about solving complex technical challenges, learning emerging technologies, and developing software that directly supports mission success, this is an exciting opportunity to grow your career while making a meaningful difference.

Position may be performed in the following locations below. Please note Gaithersburg, MD is the program’s primary work location.

• Gaithersburg, MD
• Alexandria, VA
• Chantilly, VA
• Englewood, CO
• St. Louis, MO
• Tucson, AZ

Active Top Secret/SCI with the ability to successfully pass a Polygraph examination.

• Design, develop, test, and deploy software solutions that support our customer’s GEOINT mission.
• Participate in agile development sprints and contribute to daily stand‑ups, sprint planning, and retrospectives.
• Build and maintain secure, containerized applications using technologies such as Docker, Kubernetes, and AWS.
• Develop RESTful APIs and user‑facing interfaces with modern tools (e.g., React, Node.js, Flask or Sprint Boot).
• Collaborate with mission users and product managers to refine requirements and improve user experience.
• Support DevSecOps pipelines and ensure code meets security and accreditation standards.
• Participate in code reviews and mentor junior developers as needed.
• Resolve various tasks as prioritized by the team product owner.

• US citizenship is required per contract.
• Bachelor’s degree in Computer Science, Software Engineering, or related field and 4‑8 years of prior relevant experience or Master’s with 2‑6 years of prior relevant experience.
• Active Top Secret/SCI with the ability to successfully pass a Polygraph examination.
• Proficiency with the following technologies:
  • Web: HTML, CSS, JSON, Ajax, and REST APIs
  • Object‑oriented Programming: Python, Java, or JavaScript
  • Advanced Programming: Go
  • Front‑end and Back‑end Frameworks: React, Angular, Vue.js, jQuery, Spring Boot, Django, Node.js, Flask, or Svelte
  • Cloud Development: AWS, Azure, or similar cloud platforms
  • Relational Database: MySQL, PostgreSQL, or SQL Server
  • Operating System: Windows, Linux
  • Version Control System: Git
• Deep understanding of modern software design patterns and coding standards.
• Experience architecting, developing, and delivering complex software systems into production.
• Experience with CI/CD tools (GitLab CI, Jenkins) and agile collaboration tools (JIRA, Confluence).
• Familiarity with cloud environments such as AWS (C2S or GovCloud) and containerization technologies (Docker, Kubernetes).
• Understanding of secure coding practices and government system accreditation processes (e.g., RMF, STIGs).
• Strong, self‑motivated desire to learn new programming languages, tools, frameworks, and techniques.

• Frontend Web Development: UI/UX
• NoSQL Database: OpenSearch/Elasticsearch.
• Cloud Exposure:
  • Multi‑cloud architectures: AWS, IBM, Google, Azure, and Oracle.
  • Specific AWS Services: S3, SQS, SNS, EC2, CloudFormation and RDS.
• Experience working on a customer contract or in the Intelligence Community (IC).
• Familiarity with geospatial tools and standards:
  • GeoServer
  • PostGIS
  • OGC APIs
  • ESRI ArcGIS
• Exposure to Infrastructure‑as‑Code (Terraform, Ansible)
• Certifications such as AWS Certified Developer, Security+, SAFe Practitioner or similar.

All qualified applicants will receive consideration for employment without regard to sex, race, ethnicity, age, national origin, citizenship, religion, physical or mental disability, medical condition, genetic information, pregnancy, family structure, marital status, ancestry, domestic partner status, sexual orientation, gender identity or expression, veteran or military status, or any other basis prohibited by law. Leidos will also consider for employment qualified applicants with criminal histories consistent with relevant laws.