Senior Software Engineer

in high-performance client-side scripts using Vanilla JavaScript, ensuring compatibility and minimal impact across diverse customer websites.
Optimize cross-browser rendering, troubleshoot performance issues, and implement best practices for browser behavior and security.
Build and maintain backend services using Node.js, focusing on scalability, reliability, and maintainability.
Collaborate with product managers, designers, and engineers to define technical requirements and deliver impactful solutions.
Participate in architectural discussions and contribute to the evolution of both frontend and backend systems.
Ensure high code quality through code reviews, testing, and adherence to best practices.
Work with infrastructure components such as Redis, OpenSearch, AWS services, and Kubernetes.
Support observability and performance monitoring using tools like Grafana and Prometheus.
Contribute to initiatives around script safety, measuring and minimizing impact on web page performance across various environments.

What You Bring

• 5+ years of experience in JavaScript, with strong expertise in Vanilla JS for browser environments and Node.js for backend development.
• Solid understanding of browser internals, HTTP, performance optimization, and security.
• Experience working in production environments with real users and high-scale systems.
• Familiarity with client-side frameworks (e.g., React, Angular, Vue) and front-end build tools (e.g., Grunt, Webpack).
• Hands-on experience with Kubernetes, Redis, OpenSearch, and AWS/GCP/Azure.
• Knowledge of SQL/NoSQL databases (e.g., MySQL, Redis).
• Strong communication skills and a collaborative mindset.
• B.Sc. in Computer Science or equivalent practical experience.

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.