Lead Software Engineer

Posted:
4/16/2026, 7:41:50 AM

Location(s):
O’Fallon, Missouri, United States ⋅ Missouri, United States

Experience Level(s):
Expert or higher ⋅ Senior

Field(s):
Software Engineering

Workplace Type:
On-site

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

Lead Engineer, Full Stack Engineer
Overview

We are looking for a Lead Engineer who is a hands-on full stack engineer responsible for leading design and development within a team or domain area. This role actively codes, drives high quality delivery, and provides technical guidance to the team while aligning with broader architectural direction set by Principal Engineers and Architects. The ideal candidate has experience building scalable services, modernizing legacy platforms, and contributing to GenAI enabled capabilities in an enterprise environment.

What You Will Do

Build, enhance, and maintain secure, production grade software, writing clean, testable, and maintainable code
Lead technical design and implementation for team owned services and components across the full stack
Implement service APIs, data models, and integrations aligned with established platform architecture and standards
Contribute to GenAI enabled features, including LLM integration, retrieval augmented generation patterns, embeddings, and vector stores, under guidance of broader architecture
Drive modernization of legacy components within the team’s scope using approved architectural patterns
Participate throughout the SDLC including design, development, code reviews, testing, documentation, deployment, and production support
Own operational stability of assigned services, including monitoring, incident resolution, and root cause analysis
Apply secure coding, privacy, and responsible AI practices in alignment with enterprise policies
Mentor and support engineers through code reviews, design discussions, and day to day technical guidance
Collaborate with product owners, platform teams, data teams, and security partners to deliver end to end solutions
Continuously improve engineering practices, quality, and team level technical standards

What You Bring

Bachelor’s degree in Computer Science or a related field, or equivalent practical experience
Strong foundation in data structures, algorithms, and distributed system fundamentals
7 to 10 years of hands on experience building enterprise applications using Java, Spring Framework, REST based services, and batch processing frameworks such as Spring Batch
Working experience with GenAI solutions, including LLM consumption, prompt design, retrieval augmented generation workflows, and embeddings
Experience using managed LLM platforms such as Azure OpenAI or equivalent enterprise offerings
Solid experience with relational databases, including Oracle SQL, PL SQL, data modeling, and query performance tuning
Experience working in Agile delivery models such as Scrum or SAFe, with exposure to TDD or BDD practices
Practical DevOps experience including CI CD pipelines, basic automation, logging, monitoring, and production support
Experience operating and troubleshooting applications on Linux or UNIX environments
Proven experience building reliable, scalable services within a larger distributed ecosystem
Experience contributing to modernization initiatives of legacy systems
Strong understanding of software design principles such as SOLID, separation of concerns, and clean code
Good communication skills, able to clearly explain technical designs and tradeoffs within the team
Exposure to cloud native platforms such as PCF, OpenShift, Azure, or similar environments is a plus

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 [email protected] 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