Low Level Software Developer Jobs in Missouri (NOW HIRING)

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
Lead Software Engineer
Overview
Mastercard is a global technology company in the payments industry, focused on powering an inclusive, digital economy that makes transactions safe, simple, smart, and accessible. Using secure data and networks, our innovations enable individuals, financial institutions, governments, and businesses worldwide to realize their greatest potential.
About the Role
The Secure Access team within the Technology organization is seeking a Lead Software Engineer to lead the architecture and design of microservices responsible for both API and web authentication authorizations. This role requires deep technical expertise, end-to-end ownership, and the ability to lead complex engineering initiatives.
Role
Software Design & Architecture
• Lead end-to-end software design and architecture, translating business and system requirements into scalable, reliable, and maintainable solutions
• Define high- and low-level design artifacts, including APIs, data models, system interactions, and component boundaries
• Establish and enforce architecture standards, design patterns, and engineering best practices across teams
• Apply deep knowledge of data structures, algorithms, and distributed system design to solve complex performance and scalability challenges
Software Development Excellence
• Own delivery of robust, secure, and high-performance software across backend platforms and frontend applications (React)
• Drive engineering excellence in coding standards, modular design, and maintainability
• Build and enhance internal developer platforms using Backstage or similar frameworks, leveraging plugin-based architectures
• Develop data-driven user interfaces that surface observability and operational insights
Testing Strategy & Quality Engineering
• Define and implement comprehensive testing strategies, including:
---Unit testing
---Integration testing
---Functional/end-to-end testing
• Embed automated testing within CI/CD pipelines to enforce quality gates and prevent regressions
• Ensure systems meet correctness, reliability, and backward compatibility requirements at scale
Performance Engineering
• Lead performance engineering initiatives, including system benchmarking, load testing, and capacity planning
• Analyze system bottlenecks and optimize latency, throughput, and resource utilization across distributed architectures
• Ensure applications meet strict performance SLAs in high-volume, mission-critical environments
Secure Coding & Compliance
• Enforce secure coding practices and integrate security into every phase of the SDLC
• Design systems that meet enterprise security, regulatory, and compliance requirements
• Partner with security teams to proactively identify and remediate vulnerabilities
Troubleshooting & Incident Management
• Serve as a senior escalation point for complex production issues across distributed systems and user-facing platforms
• Lead root cause analysis, incident resolution, and postmortem activities
• Drive systemic improvements to prevent recurring issues and improve system reliability
Code Review & Technical Leadership
• Lead rigorous code reviews, ensuring adherence to best practices in design, performance, security, and maintainability
• Mentor engineers and elevate team capability in software design, testing, debugging, and operational excellence
• Provide hands-on guidance in solving high-complexity technical problems across system layers
Collaboration & Ownership
• Partner with product, platform, and business stakeholders to shape technical roadmaps and delivery priorities
• Own and deliver cross-functional initiatives spanning frontend, backend, and platform engineering
• Contribute to the Software Engineering Guild by sharing reusable frameworks, patterns, and innovations
All About You
We are looking for someone who:
• Demonstrates deep expertise across software development, system design, and architecture
• Brings a strong foundation in data structures, algorithms, and distributed systems
• Leads with a quality-first mindset, emphasizing testing, security, and performance
• Excels at troubleshooting complex systems and driving resolution under pressure
• Proactively improves operability, reliability, and developer experience
• Influences technical direction and mentors' engineers across teams
Qualifications:
• Strong hands-on experience with:
---Unit, Integration, and Functional Testing frameworks and strategies
---Performance Engineering and system optimization
---Secure coding practices and application security principles
---Code reviews and engineering quality standards
---Operability engineering (observability, monitoring, reliability)
• Proven experience in backend development with applicable JAVA technologies (Core JAVA, Spring Integration, Spring Boot, Hibernate, REST/SOAP web services)
• Proven experience working with Oracle/SQL Databases
• Extensive experience in software development and system design, data structures, algorithms, and a demonstrated ownership to maintain and troubleshoot complex large-scale distributed systems
• Experience in technical design activities to ensure alignment with Non-Functional Requirements, Solution Architecture and System Functional Design specifications
• Hands-on experience with AWS (Azure a plus), Kubernetes, and cloud-native technologies
• Strong experience with CI/CD pipelines and Infrastructure as Code (Terraform, CloudFormation)
• Experience with observability platforms (e.g., Splunk or equivalent)
• Excellent communication and technical leadership skills
• Bachelor's or Master's degree in Computer Science, Engineering, or related field preferred
• Knowledge and experience working within the security/ access domain is preferred
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.
Pay Ranges
O'Fallon, Missouri: $140,000 - $231,000 USD