Senior Integration Engineer Job O'Fallon area,Missouri USA,Software Development

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 Senior Integration Engineer Overview

At Mastercard, our technology and innovation are driven by a clear purpose: to build a sustainable, inclusive global economy. Our commitment to being a force for good is embedded in The Mastercard Way—the principles and behaviors that define who we are and how we deliver value to our customers, partners, and communities. We foster a highly collaborative and inclusive environment where employees are empowered to bring their full, authentic selves to work.

By leveraging the diverse strengths, perspectives, and experiences of our global workforce, we continue to drive innovation at scale.

Role Summary

The Pricing & Billing Resource Center (PBRC) team develops and operates business-critical, API-driven platforms built on Java and Spring technologies. These platforms power highly scalable and reliable billing and pricing services across Mastercard. Quality engineering is central to ensuring functional correctness, API integrity, UI reliability, and performance s role is an automation-first Senior SDET position, responsible for designing, building, and maintaining robust automated test frameworks across API, UI, and performance layers.

You will work closely with engineering teams to embed quality throughout the SDLC, ensuring speed, stability, and confidence in every release.

Key Responsibilities

Automation Ownership (API & UI)

Design and maintain scalable, maintainable test automation frameworks using:
Java + Selenium (UI automation)
REST Assured (API automation)
Cucumber (BDD) for executable specifications
Cypress for modern UI testing where applicable
Ensure automation suites are reliable, efficient, and aligned with engineering standards

API Quality Engineering

Validate REST APIs built on Spring / Spring Boot for functional correctness
Contract/schema adherence
Error handling and edge cases
Utilize Postman and Insomnia for exploratory testing and debugging, converting findings into automated coverage

Performance & Non-Functional Testing

Design and execute performance, load, and stress tests using tools such as JMeter and Blaze Meter
Define and track performance baselines across throughput, latency, Resource utilization
Partner with engineering teams to diagnose bottlenecks and optimize performance

CI/CD Integration

Integrate automation suites into CI/CD pipelines to provide rapid feedback and enforce quality gates
Enable parallel execution and efficient test runs across shared environments

Test Strategy & Quality Leadership

Contribute to test strategy, coverage planning, and risk assessment
Create high-quality defect reports with clear diagnostics and reproducibility
Lead improvements in test frameworks, processes, and engineering standards
Provide technical leadership and mentorship across QA and delivery teams

Required Qualifications

6+ years of experience in automation-focused QA / SDET roles
Strong hands-on expertise in Java-based automation frameworks
Deep experience with Selenium (UI automation)
Deep experience with REST Assured (API testing)
Deep experience with Cucumber (BDD frameworks)
Deep experience with Cypress (modern UI automation)
Strong understanding of Spring / Spring Boot microservices architectures
Experience testing RESTful APIs in distributed…