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Per Diem Software Engineer Jobs in Missouri (NOW HIRING)

Senior Software Engineer

O Fallon, MO · On-site +1

$114K - $151K/yr

... requests per second, P95 and P99 response latency, query performance, concurrency, and system ... software engineering experience writing applications using Java Spring Boot framework Strong ...

Mid-Level Software Engineer

Fenton, MO · On-site

$87K - $157K/yr

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

Mid-Level Software Engineer

Arnold, MO · On-site

$87K - $157K/yr

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

Mid-Level Software Engineer

Ballwin, MO · On-site

$87K - $157K/yr

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 ...

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 ...

Showing results 21-40

Per Diem Software Engineer information

See Missouri salary details

$59.6K

$138.4K

$192.8K

How much do per diem software engineer jobs pay per year?

As of Aug 16, 2026, the average yearly pay for per diem software engineer in Missouri is $138,378.00, according to ZipRecruiter salary data. Most workers in this role earn between $112,600.00 and $162,300.00 per year, depending on experience, location, and employer.

What is the difference between Per Diem Software Engineer vs Contract Software Engineer?

AspectPer Diem Software EngineerContract Software Engineer
CredentialsTypically requires a bachelor's degree in CS or related fieldSimilar educational requirements, often with specific technical skills
Work EnvironmentTemporary, short-term assignments often on-site or remoteProject-based, short to medium-term engagements, on-site or remote
Employer UsageUsed by government agencies, hospitals, or large organizations for temporary staffingCommon in tech firms, consulting agencies, and startups for project needs

Per Diem Software Engineers and Contract Software Engineers both work on temporary assignments, often requiring similar skills and credentials. The main difference lies in their typical employment arrangements and usage by different organizations. Per Diem roles are often associated with government or healthcare sectors, while Contract roles are prevalent in tech and consulting industries.

What are the most commonly searched types of Software Engineer jobs in Missouri?

The most popular types of Software Engineer jobs in Missouri are:

What cities in Missouri are hiring for Per Diem Software Engineer jobs?

Cities in Missouri with the most Per Diem Software Engineer job openings:

Infographic showing various Per Diem Software Engineer job openings in Missouri as of June 2026, with employment types broken down into 2% As Needed, 80% Full Time, 1% Part Time, and 17% Contract. Highlights an 99% Physical, and 1% Remote job distribution, with an average salary of $138,378 per year, or $66.5 per hour.

Senior Software Engineer

MasterCard

O Fallon, MO • On-site, Remote

$114K - $151K/yr

Full-time

Medical, Dental, Vision, Life, Retirement, PTO

Re-posted 9 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 asustainableeconomy where everyone can prosper. We support a wide range of digital payments choices, making transactionssecure, 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

Senior Software EngineerOverview
We work 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. We cultivate a culture of inclusion for all employees that respect their individual strengths, views, and experiences. We believe that our differences enable us to be a better team - one that makes better decisions, drives innovation, and delivers better business results
About the Role
This is an exciting opportunity for you to join Mastercard and contribute to improving the response time for new applications that support the Authorization payment network. This position is on the performance engineering team that partners with development teams on optimization and testing. We are looking for an experienced engineer that is passionate about performance with a constant focus on improving system quality.
Role
Design, configure, and execute performance tests and drive resolution of failures
Create performance measurements such as requests per second, P95 and P99 response latency, query performance, concurrency, and system utilization
Dig into Java code, databases, middleware, and vendor software to identify performance bottlenecks and resolve them
Improve the performance environment with your own code, automation, and external tools
Apply technical ability to coach and develop junior engineers
Deliver department and external presentations sharing results with stakeholders
All About You
Strong software engineering experience writing applications using Java Spring Boot framework
Strong experience debugging performance issues with APM tools (i.e. Dynatrace, Splunk, Jprofiler, and JMH)
Strong experience optimizing DB queries in PostgreSQL and Oracle
Experience with Payments industry preferred (i.e. ISO 8583 messaging, 4-party model, and payment applications)
Systematic problem-solving approach, coupled with strong communication skills and a sense of ownership and drive
Time/project management, workload prioritization, knowledge sharing and a passion to learn/take on challenges is a must
Self-motivated demonstrating strong organizational and listening skills; and very detail oriented with the ability to carry out assigned tasks with minimal supervision
Strong verbal and written communications skills
Appetite for change and pushing the boundaries of what can be done with automation. Be curious about new technology, infrastructure, and practices to scale our architecture and prepare for future growth
Willingness and ability to learn and take on challenging opportunities and to work as a member of matrix based diverse and geographically distributed project teamMastercard 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.

Pay Ranges

O'Fallon, Missouri: $115,000 - $184,000 USD