**Overview**

The _Core Services Infrastructure and Security_ team in Microsoft Teams provides the foundational compute, network, security, routing, traffic management, and governance layers that power Microsoft’s real‑time communication experiences across the globe.

As a **Senior Site Reliability Engineer** , you will help build and operate the mission‑critical components of our distributed systems platform ensuring that Teams remains fast, reliable, secure, and resilient at global scale. You will focus on areas such as network security, front door and gateway infrastructure, routing and load balancing, DNS and CDN systems, and end‑to‑end monitoring and observability.

This is a unique opportunity to deepen your expertise across high‑scale, active‑active architectures while collaborating with seasoned engineers who obsess over reliability and defense‑in‑depth. You will contribute hands‑on implementation work, participate in design discussions, and apply eng...