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Entry Level Computer Science Jobs in O Fallon, MO

Software Engineer II

O Fallon, MO · On-site

$92K - $147K/yr

A Software Engineer II is an early-career or entry-level engineer who contributes to the design ... Bachelor's degree in computer science, Engineering, Information Technology, or equivalent ...

Software Engineer II

O Fallon, MO · On-site

$91K - $124K/yr

A Software Engineer II is an early-career or entry-level engineer who contributes to the design ... Bachelor's degree in computer science, Engineering, Information Technology, or equivalent ...

Software Engineer II

O Fallon, MO

$91K - $124K/yr

A Software Engineer II is an earlycareer or entrylevel engineer who contributes to the design ... computer science, Engineering, Information Technology, or equivalent experience Foundational ...

Junior Water Resources Engineer

Saint Louis, MO · On-site

$76K - $105K/yr

Overview / Responsibilities Wood is currently recruiting entry level Water Resources Engineers in ... Master of Science qualification preferred. Classwork or job/internship in the following knowledge ...

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Showing results 1-20

Entry Level Computer Science information

See O Fallon, MO salary details

$19.3K

$43.2K

$86.5K

How much do entry level computer science jobs pay per year?

As of Jun 9, 2026, the average yearly pay for entry level computer science in O'Fallon, MO is $43,226.00, according to ZipRecruiter salary data. Most workers in this role earn between $30,557.00 and $49,362.00 per year, depending on experience, location, and employer.

What Are Entry-Level Jobs in Computer Science?

Entry-level computer science jobs include positions that involve programming, software and app development, database administration, and the engineering of software and computer systems. You can also provide technical support, develop specialized programs for mobile phones or embedded computer systems, and work in areas such as cloud computing and machine learning. Entry-level computer science professionals typically operate as part of software development or IT teams, or they report to senior personnel and submit their work for testing and approval. Your duties and responsibilities often focus on developing, testing, or engineering a specific part of a computer-related project.

What are entry level computer science jobs?

Entry level computer science jobs are positions designed for individuals who have recently graduated with a computer science degree or have basic programming and technical skills. These roles typically require little to no prior professional experience and may include job titles such as software developer, IT support specialist, web developer, or quality assurance tester. Entry level positions offer opportunities to gain hands-on experience, learn from more experienced team members, and develop practical skills in areas like coding, debugging, and software development processes.

What types of projects or tasks can I expect to work on as an entry level computer science professional?

As an entry level computer science professional, you will typically work on tasks such as debugging code, writing simple programs or scripts, assisting with software testing, and supporting senior developers with larger projects. You may also be responsible for maintaining documentation, collaborating with team members during code reviews, and learning new technologies as needed. These experiences help you build a strong foundation and gain practical skills, setting the stage for more complex responsibilities and career advancement in the future.

What is the difference between Entry Level Computer Science vs Software Developer?

AspectEntry Level Computer ScienceSoftware Developer
Required CredentialsBachelor's in CS or related fieldBachelor's in CS or related field; coding bootcamps
Work EnvironmentTech companies, startups, IT departmentsTech firms, software companies, startups
Employer & Industry UsageEntry-level roles in various industriesDeveloping software applications across industries
Common Search & ComparisonYesYes

Entry Level Computer Science roles typically focus on foundational knowledge and may involve a variety of IT tasks, while Software Developer positions emphasize designing, coding, and maintaining software applications. Both roles often require similar educational backgrounds, but Software Developers usually have more specialized coding skills and project responsibilities.

What are the key skills and qualifications needed to thrive as an Entry Level Computer Science professional, and why are they important?

To thrive as an Entry Level Computer Science professional, you need a solid understanding of programming languages (such as Python, Java, or C++), algorithms, and data structures, typically supported by a bachelor’s degree in computer science or a related field. Familiarity with version control systems like Git, basic software development tools, and potentially certifications like CompTIA IT Fundamentals can be beneficial. Strong problem-solving abilities, attention to detail, and effective communication skills help you collaborate and adapt to new challenges. These skills are crucial for efficiently developing, testing, and maintaining software solutions in a team-oriented and rapidly evolving technical environment.
What are the most commonly searched types of Computer Science jobs in O'Fallon, MO? The most popular types of Computer Science jobs in O'Fallon, MO are:
What are popular job titles related to Entry Level Computer Science jobs in O'Fallon, MO? For Entry Level Computer Science jobs in O'Fallon, MO, the most frequently searched job titles are:
What cities near O'Fallon, MO are hiring for Entry Level Computer Science jobs? Cities near O'Fallon, MO with the most Entry Level Computer Science job openings:
Infographic showing various Entry Level Computer Science job openings in O'Fallon, MO as of June 2026, with employment types broken down into 79% Full Time, and 21% Part Time. Highlights an 100% In-person job distribution, with an average salary of $43,226 per year, or $20.8 per hour.
Software Engineer II

Software Engineer II

Mastercard, Inc.

O Fallon, MO • On-site

$92K - $147K/yr

Full-time

Medical, Dental, Vision, Life, Retirement, PTO

Posted 17 days ago


Job description

Our Purpose
Mastercard powers economies and empowers people in 200+ countries and territories worldwide. Together with our customers, we're helping build a sustainable economy where everyone can prosper. We support a wide range of digital payments choices, making transactions secure, simple, smart and accessible. Our technology and innovation, partnerships and networks combine to deliver a unique set of products and services that help people, businesses and governments realize their greatest potential.
Title and Summary
Software Engineer II
Who is Mastercard?
Mastercard is a global technology company in the payments industry. Our mission is to connect and power an inclusive, digital economy that benefits everyone, everywhere by making transactions safe, simple, smart, and accessible. Using secure data and networks, partnerships and passion, our innovations and solutions help individuals, financial institutions, governments, and businesses realize their greatest potential.
Our decency quotient, or DQ, drives our culture and everything we do inside and outside of our company. With connections across more than 210 countries and territories, we are building a sustainable world that unlocks priceless possibilities for all.
Overview
The Decision Management Program (DMP) delivers industry-leading intelligence that enables faster, smarter decisioning at global scale across the payment journey and beyond. Through a suite of products, DMP structures and applies complex business logic to help teams manage risk, adapt quickly to changing regulatory, geopolitical, or market conditions, and drive profitable customer engagements. Built for resiliency, availability, and future growth, DMP empowers Mastercard's market-facing programs with agile, intelligent decision management capabilities worldwide.
A Software Engineer II is an early-career or entry-level engineer who contributes to the design, development, testing, and maintenance of software solutions under the guidance of more senior engineers. This role is ideal for individuals who have a strong foundation in software development fundamentals and are eager to grow their technical skills while delivering value to real-world systems.
Software Engineer II roles follow clearly defined guidelines and focus on building core engineering skills, understanding enterprise systems, and learning Mastercard's engineering standards and processes.
Role
• The role provides foundational exposure to secure, scalable service development, encryption technologies, and enterprise engineering standards. Working within Agile delivery teams, the Software Engineer II collaborates with experienced engineers to help deliver high-quality, reliable, and security-critical software components.
• Contribute to the design, development, testing, and implementation of software solutions under guidance from senior engineers
• Develop and maintain application code in accordance with established engineering, quality, and security standards
• Create and execute unit tests and support automated testing efforts
• Participate in code reviews and incorporate feedback
• Assist with troubleshooting, defect resolution, and application support
• Collaborate with cross-functional teams to deliver assigned work on schedule
• Adhere to audit, compliance, and information security requirements
All About You / Experience
• Bachelor's degree in computer science, Engineering, Information Technology, or equivalent experience
• Foundational knowledge of software engineering concepts and the software development lifecycle
• Experience with one or more programming languages (Java is a must)
• Familiarity with Agile development practices, testing concepts, and version control
• Strong analytical, problem-solving, and communication skills
• Ability to work effectively in a collaborative, team-based environment
Willingness to learn new technologies and tools
#LI-FT1
Pay Ranges
O'Fallon, Missouri: $92,000 - $147,000 USD
Mastercard is a merit-based, inclusive, equal opportunity employer that considers applicants without regard to gender, gender identity, sexual orientation, race, ethnicity, disabled or veteran status, or any other characteristic protected by law. We hire the most qualified candidate for the role. In the US or Canada, if you require accommodations or assistance to complete the online application process or during the recruitment process, please contact reasonable_accommodation@mastercard.com and identify the type of accommodation or assistance you are requesting. Do not include any medical or health information in this email. The Reasonable Accommodations team will respond to your email promptly.
Corporate Security Responsibility
All activities involving access to Mastercard assets, information, and networks comes with an inherent risk to the organization and, therefore, it is expected that every person working for, or on behalf of, Mastercard is responsible for information security and must:
  • Abide by Mastercard's security policies and practices;
  • Ensure the confidentiality and integrity of the information being accessed;
  • Report any suspected information security violation or breach, and
  • Complete all periodic mandatory security trainings in accordance with Mastercard's guidelines.
In line with Mastercard's total compensation philosophy and assuming that the job will be performed in the US, the successful candidate will be offered a competitive base salary and may be eligible for an annual bonus or commissions depending on the role. The base salary offered may vary depending on multiple factors, including but not limited to location, job-related knowledge, skills, and experience. Mastercard benefits for full time (and certain part time) employees generally include: insurance (including medical, prescription drug, dental, vision, disability, life insurance); flexible spending account and health savings account; paid leaves (including 16 weeks of new parent leave and up to 20 days of bereavement leave); 80 hours of Paid Sick and Safe Time, 25 days of vacation time and 5 personal days, pro-rated based on date of hire; 10 annual paid U.S. observed holidays; 401k with a best-in-class company match; deferred compensation for eligible roles; fitness reimbursement or on-site fitness facilities; eligibility for tuition reimbursement; and many more. Mastercard benefits for interns generally include: 56 hours of Paid Sick and Safe Time; jury duty leave; and on-site fitness facilities in some locations.