Top 76 Java developer Jobs in O'fallon, Mo

Mid-Level Backend Software Engineer
Leidos —St. Louis, MO
- $87,100 - $157,450 a year
- Full-time
- Azure
- Computer Science
- System design
Mid-Level Software Engineer
Leidos —St. Louis, MO
- $87,100 - $157,450 a year
- Full-time
- Azure
- Computer Science
- Mid-level
12d
Experienced Software Development Engineer
Boeing —Hazelwood, MO
- $126,650 - $171,350 a year
- Computer science
- Computer Science
- Bachelor of Science
- Health savings account
- Disability insurance
Experienced Software Development Engineer
Boeing —Berkeley, MO
- $126,650 - $171,350 a year
- Computer science
- Computer Science
- Bachelor of Science
- Health savings account
- Disability insurance
Lead Software Engineer, Phantom Works
Boeing —Berkeley, MO
- $160,650 - $217,350 a year
- Computer science
- Computer Science
- Bachelor of Science
- Health savings account
- Disability insurance
Software Engineer I
Mastercard —O'Fallon, MO
- $72,000 - $115,000 a year
- Online Application
- Computer science
- Computer Science
- System design
- Paid jury duty
- Health savings account
1d
Software Engineer II
Mastercard —O'Fallon, MO
- $92,000 - $147,000 a year
- Online Application
- Research
- Mid-level
- Analysis skills
- Paid jury duty
- Health savings account
5d
Senior Software Engineer
Mastercard —O'Fallon, MO
- $115,000 - $184,000 a year
- Online Application
- Mentoring
- Senior level
- Leadership
- Paid jury duty
- Health savings account
Software Developer (Hiring Event)
National Geospatial-Intelligence Agency —St. Louis, MO
- $76,573 - $141,880 a year
- Online Application
- Computer Science
- Pass drug screening
- Mid-level
9d
BackEnd Software Engineer (Experienced or Senior)
Boeing —Berkeley, MO
- $126,650 - $217,350 a year
- Computer science
- Computer Science
- 5 years
- Health savings account
- Disability insurance
8d
Flight Simulation Software Engineers (Associate, Experienced, and Senior)
Boeing —Berkeley, MO
- $94,450 - $217,350 a year
- Java
- Bachelor's degree
- Computer networking
- Health savings account
- Disability insurance
8d
Senior Application Support Engineer (Java, SQL & Production Support)
Apexon —St. Louis, MO
- $78,780.01 - $94,874.85 a year
- Full-time
- Hybrid work
- Mid-level
- Java
- SQL
- Health insurance
- Dental insurance
Quick Apply
Mission Software Engineer (Experienced or Senior)
Boeing —Berkeley, MO
- $126,650 - $217,350 a year
- Computer science
- Computer Science
- 5 years
- Health savings account
- Disability insurance
Lead Developer Platforms Software Engineer
Boeing —Berkeley, MO
- $198,050 - $267,950 a year
- Computer science
- Azure
- 6 years
- Health savings account
- Disability insurance
F-15 Mission Systems Software Engineer (Associate, Experienced, & Senior)
Boeing —Berkeley, MO
- $99,450 - $217,350 a year
- Computer science
- Computer Science
- Software troubleshooting
- Health savings account
- Disability insurance
Senior Software Development Engineer
Mastercard —O'Fallon, MO
- $115,000 - $184,000 a year
- Online Application
- Research
- Analysis skills
- Mentoring
- Paid jury duty
- Health savings account
5d
Software Developer II - Financials (Full Stack, Front End)
National Information Solutions Cooperative (NISC) —Lake Saint Louis, MO
- Hybrid work
- Computer science
- Computer Science
- Customer service
- Health savings account
- Paid holidays
23h
Senior Software Engineer - Java Full Stack Engineer
Mastercard —O'Fallon, MO
- $115,000 - $184,000 a year
- Online Application
- Computer science
- 7 years
- Computer Science
- Paid jury duty
- Health savings account
Entry - Level Software Engineer
Boeing —Berkeley, MO
- $78,200 - $105,800 a year
- Computer Science
- Bachelor of Science
- Java
- Health savings account
- Disability insurance
2d
Full Stack Senior Developer C#/ASP.Net/React
Centerprism —St. Louis, MO
- $79,619 - $109,886 a year
- Part-time
- Hybrid work
- Azure
- Java
- AWS
- AD&D insurance
- Health insurance
Quick Apply
2d

I want to receive the latest job alert for java developer in o'fallon, mo

By signing in to your account, you agree to SimplyHired's Terms of Service and consent to our Cookie and Privacy Policy.

Explore jobs in more locations

java developer jobs near o'fallon, mo

Entry Level Software Engineer jobs in St. Louis, MO

Senior Software Engineer jobs in O'Fallon, MO

Software Engineer jobs in O'Fallon, MO

Software Engineer jobs in St. Louis, MO

Platform Engineer jobs in Berkeley, MO

Full Stack Developer jobs in St. Louis, MO

Software Engineer jobs in Hazelwood, MO

Back End Developer jobs in St. Louis, MO

Mechanical Engineer jobs in San Luis Obispo, CA

Entry Level Software Engineer jobs in Bothell, WA

Entry Level Software Engineer jobs in Huntington Beach, CA

Entry Level Ux Designer jobs in Seattle, WA

Quality Engineer jobs in El Paso, TX

Entry Level Software Engineer jobs in Brevard County, FL

Entry Level Software Engineer jobs in Palmdale, CA

Senior Software Engineer jobs in Bothell, WA

Senior Software Engineer jobs in Wilmington, NC

Brightview Senior Living jobs in Shelton, CT

Senior Software Engineer jobs in Redmond, WA

Software Engineer jobs in Newark, DE

Mid-Level Backend Software Engineer

Leidos -
St. Louis, MO

Apply Now

Job Details

Full-time
$87,100 - $157,450 a year

Qualifications

SQL
Linux
Query management

Full Job Description

Description

If you’ve been building your skills in backend development, object‑oriented programming, and mission‑driven engineering, and you’re ready for work that actually moves the needle, this is the kind of opportunity cleared engineers pursue when they want to grow while making real impact. If you take pride in your craft, enjoy solving meaningful technical problems, and want your work to support a mission with visibility at senior levels, you’ll thrive here.

We’re hiring a Backend Software Engineer to support a high‑visibility, data‑driven application used across the organization for analytics and reporting. You’ll help build and maintain core backend services, develop RESTful APIs, support data‑driven functionality, and contribute to ongoing system enhancements within a Linux‑based environment. Your work will directly support system reliability, performance, and data accuracy for mission stakeholders. Our primary development team operates out of Gaithersburg, MD, but we also support onsite engineers in Chantilly, VA, Alexandria, VA; Aurora, CO; St. Louis, MO; and Tucson, AZ, giving top talent multiple paths to join the mission.

And while the requisition requirements may seem standard fare, the position is not; as it will join a high performing team that is changing the way digital engineering and mission operations intelligence is enabled for our customer.

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

Essential 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

Basic Qualifications

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

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

#MARU

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:

April 16, 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 $87,100.00 - $157,450.00

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.

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.

Pay and Benefits

Pay and benefits are fundamental to any career decision. That's why we craft compensation packages that reflect the importance of the work we do for our customers. Employment benefits include competitive compensation, Health and Wellness programs, Income Protection, Paid Leave and Retirement. More details are available at www.leidos.com/careers/pay-benefits.

Securing Your Data

Beware of fake employment opportunities using Leidos’ name. Leidos will never ask you to provide payment-related information during any part of the employment application process (i.e., ask you for money), nor will Leidos ever advance money as part of the hiring process (i.e., send you a check or money order before doing any work). Further, Leidos will only communicate with you through emails that are generated by the Leidos.com automated system – never from free commercial services (e.g., Gmail, Yahoo, Hotmail) or via WhatsApp, Telegram, etc. If you received an email purporting to be from Leidos that asks for payment-related information or any other personal information (e.g., about you or your previous employer), and you are concerned about its legitimacy, please make us aware immediately by emailing us at [email protected].

If you believe you are the victim of a scam, contact your local law enforcement and report the incident to the U.S. Federal Trade Commission.

Commitment to Non-Discrimination

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.

#Featuredjob

Apply Now

Refine Your Search

java developer jobs in o'fallon, mo

Mid-Level Backend Software Engineer

Mid-Level Software Engineer

Experienced Software Development Engineer

Experienced Software Development Engineer

Lead Software Engineer, Phantom Works

Software Engineer I

Software Engineer II

Senior Software Engineer

Software Developer (Hiring Event)

BackEnd Software Engineer (Experienced or Senior)

Flight Simulation Software Engineers (Associate, Experienced, and Senior)

Senior Application Support Engineer (Java, SQL & Production Support)

Mission Software Engineer (Experienced or Senior)

Lead Developer Platforms Software Engineer

F-15 Mission Systems Software Engineer (Associate, Experienced, & Senior)

Senior Software Development Engineer

Software Developer II - Financials (Full Stack, Front End)

Senior Software Engineer - Java Full Stack Engineer

Entry - Level Software Engineer

Full Stack Senior Developer C#/ASP.Net/React

I want to receive the latest job alert for java developer in o'fallon, mo

Related Searches

Explore jobs in more locations

Original Posting:

Pay Range:

Job Seeker Tools

Employer Tools

Browse

Stay Connected