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# Senior Software Engineer

- **Company:** Mastercard
- **Location:** O'Fallon, MO, United States
- **Experience:** Expert
- **Salary:** $115,000 - $184,000
- **Contract:** Permanent contract
- **Skills:** Java (Programming Language), Microsoft Excel, Application Programming Interfaces (APIs), Agile Methodology, Amazon Web Services, Application Integration Architecture, Automation of Tests, Microsoft Azure, Cloud Computing, Cloud Engineering, Code Review, Cyber Security, Continuous Integration, Data Structures, Software Design Patterns, DevOps, Distributed Systems, Payment Systems, Github, Spring Framework, Junit, Key Management, PostgreSQL, Apache Maven, MongoDB, OAuth, Object-Oriented Software Development, Oracle (Applications), Open Web Application Security, PCI Data Security Standards, Performance Tuning, Public Key Infrastructure, Redis, Reliability Engineering, Site Reliability Engineering Practices, Mockito, Prometheus, RSA (Cryptosystem), Secure Coding, Software Engineering, Openapi, Enterprise Data Management, Transaction Processing (Computing), Java Application Server, Enterprise Software Applications, Azure Data Factory, Spring Cloud, Grafana, Spring-boot, Software Security, Reliability of Systems, Backend, Event Driven Architecture, Containerization, Integration Tests, Solid Principles, Kubernetes, Deployment Automation, Apache Kafka, Restful APIs, Splunk, Spring Batch, Dynatrace, Docker, Jenkins, Programming Languages, Microservices
- **Published:** November 8, 2026
- **Apply:** https://www.careerbuilder.com/job-details/senior-software-engineer-o-fallon-mo--91eaef52-e097-4402-904f-f79a01f593c0

## About the Role

Software Engineering, Time Management, Use Cases, Disbursements, Business Banking, Distributed Computing, Systems Reliability, Software Engineering, Reliability Engineering, Java, * Deep hands-on experience building Java-based distributed systems, with strong knowledge of performance, scalability, and resiliency principles.

 * Experience developing enterprise applications using Java, Spring Boot, microservices, and cloud-native technologies.
 * Experience translating business requirements into technical designs, architecture decisions, and API specifications.
 * Strong understanding of Agile, DevOps, CI/CD, and modern software delivery practices.
 * Experience applying data structures, software design principles, code reviews, secure coding practices, and automated testing (unit, functional, and integration) to build reliable, maintainable solutions. [Senior SE Skills | Excel]
 * Experience with production support, on-call operations, incident management, root cause analysis, and service ownership.
 * Experience implementing observability and monitoring solutions using tools such as OpenTelemetry and Dynatrace.
 * Experience with encryption, secrets management, API security, and enterprise data protection standards.
 * Experience with performance tuning, capacity planning, resiliency testing, and support of high-volume transaction systems.
 * Hands-on experience supporting containerized workloads on Kubernetes, PCF, AWS, or Azure.
 * Experience working in payment processing, financial services, or other high-volume transaction environments is preferred.

Key Technical Skills

Languages & Frameworks

 * Java, Spring Framework, Spring Boot, Spring Batch, Spring Cloud

Architecture & Integration

 * Microservices, REST APIs, Event-Driven Architecture, Apache Kafka
 * Object-Oriented Design, Design Patterns, Data Structures [Senior SE Skills | Excel]

Reliability & Security

 * SRE, SLIs, SLOs, Error Budgets, Incident Response, Root Cause Analysis
 * OAuth2, AES/RSA, TLS/PKI, Secure Coding (OWASP, PCI-DSS)

Cloud & Infrastructure

 * Kubernetes, Docker, PCF, AWS, Azure

Data Technologies

 * Oracle, PostgreSQL, Redis, MongoDB

DevOps & Observability

 * Jenkins, GitHub, Maven, CI/CD
 * OpenTelemetry, Dynatrace, Splunk, Prometheus, Grafana

Testing

 * JUnit, Mockito, Karate
 * Unit, Functional, and Integration Testing

## Description

As a Java Site Reliability Engineer (SRE) within the Mastercard Send team, you will play a critical role in designing, building, and operating highly resilient payment platforms that power near real-time money movement across the globe. You will combine strong software engineering expertise with operational excellence practices to ensure the reliability, scalability, security, and performance of mission-critical payment systems.

Role Responsibilities

 * Design, develop, deploy, and support cloud-native Java applications and microservices that power Mastercard Send solutions.
 * Build scalable, resilient systems using distributed architecture and cloud-native design patterns.
 * Develop and maintain secure, high-performing APIs and backend services.
 * Drive production reliability through observability, monitoring, incident response, and continuous improvement.
 * Implement and champion SRE practices, including SLIs, SLOs, Error Budgets, and production readiness reviews.
 * Automate deployments, testing, monitoring, and operational processes to improve reliability and reduce manual effort.
 * Partner with product, platform, infrastructure, and security teams to deliver secure, scalable solutions.
 * Optimize application and platform performance to support high-volume, real-time transaction processing workloads.
 * Mentor engineers and promote software engineering and operational excellence best practices., 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.