Junior software developer Jobs in St Louis, MO

The Leidos FS2 Aero team has an opening for a junior software developer to work on the design and coding with software solutions for the Aeronautical Navigation Office for 6 month – temporary to permanent hire position. The ideal candidate has a familiarity with and a baseline understanding of software development concepts, developing coding skills using different tools, and ambition towards future projects in support of the mission.

Primary Responsibilities

• Primary responsibilities will involve building software coding knowledge providing the system administration and modification of existing GOTS code to integrate open-source software solutions for display in a web application.
• This role will work with programming languages to include C#/Java and JavaScript/TypeScript, Python, Shell scripting.
• Creation and documentation of new and existing functionality within software version control repositories (gitlab) and utilizing DevOps principals and tools to deliver new features within an Agile construct.
• Participate in program Agile software development initiatives (standup, planning, Increment planning) to support applications through iteration/functionality utilizing Atlassian (Jira/Confluence).
• Participate and collaborate with team members to assess tickets to ensure proper testing and delivery of functionality per User Story Acceptance Criteria.

Basic Qualifications

• Candidate must have an active Top Secret clearance.
• Candidate must be able to obtain a TS/SCI prior to starting.
• Candidate must be able to maintain TS/SCI and obtain a successful CI poly post hire.
• Requires BS degree or certification and 2-4 years of prior relevant experience. Experience may be considered in lieu of a degree.
• Minimum 2 year of experience with JavaScript, Python, or C# development framework.
• Minimum 2 years of experience of working with web-enabled applications.
• Proactive self-starter demonstrates a positive, willing attitude and excellent oral and written communication skills.
• Experience in either software development projects or software integration projects in a service-oriented environment (Cloud, SOA, Web-Services) or virtualization environment.
• Demonstrated ability to prioritize competing responsibilities, manage workload efficiently, and deliver high-quality work with strong attention to detail.
• Strong verbal and written communication skills, with the ability to effectively collaborate with teams and communicate complex ideas to a variety of audiences.

Preferred Qualifications

• At least 1 years of experience with DOD software requirements.
• At least 2 year of experience working in a government cloud environment.
• AWS Solutions or DevOps certification
• Team Collaboration tools (Jira, Confluence)
• Active TS/SCI with Polygraph
• DOD 8570 Compliant Certification (Sec+)

#NSBA

If you're looking for comfort, keep scrolling. At Leidos, we outthink, outbuild, and outpace the status quo — because the mission demands it. We're not hiring followers. We're recruiting the ones who disrupt, provoke, and refuse to fail. Step 10 is ancient history. We're already at step 30 — and moving faster than anyone else dares.

Original Posting:

October 23, 2026

For U.S. Positions: While subject to change based on business needs, Leidos reasonably anticipates that this job requisition will remain open for at least 3 days with an anticipated close date of no earlier than 3 days after the original posting date as listed above.

Pay Range:

Pay Range $69,550.00 - $125,725.00

The Leidos pay range for this job level is a general guideline only and not a guarantee of compensation or salary. Additional factors considered in extending an offer include (but are not limited to) responsibilities of the job, education, experience, knowledge, skills, and abilities, as well as internal equity, alignment with market data, applicable bargaining agreement (if any), or other law.