Software Development Engineer, CloudFront Routing

Amazon CloudFront is Amazon"s global content delivery network, delivering content from 400+ edge locations across 90+ cities in 48 countries. CloudFront accelerates static and dynamic web content, video streaming, APIs, and software distribution for customers ranging from startups to the world"s largest media companies. It handles live events at scale (Thursday Night Football, FIFA World Cup, Prime Video) where milliseconds of latency and seconds of availability directly impact customer experience.

We are the Routing & Capacity Engineering team within CloudFront. We build the systems that decide which POP serves each request: DNS traffic steering, real-time load measurement, latency-based routing algorithms, and capacity planning. When a viewer in Tokyo presses play, our systems determined in milliseconds which edge location would serve that stream. We operate at the intersection of distributed systems, networking, and data engineering, solving problems like: how do you optimally place traffic when latency, capacity, and cost pull in different directions? How do you react when a network event shifts traffic patterns across a continent?

You:

• Want to build systems that operate at global scale with visible customer impact
• Are comfortable with ambiguity. Problems arrive as "traffic isn"t behaving right," not as specs
• Are curious about networking, CDN architecture, and how the internet actually works
• Think about scale: real-time decisions across hundreds of locations, dozens of signals
• Own your systems end-to-end. Design, build, deploy, monitor, improve
• Learn fast and help others grow
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AWS Infrastructure Services owns the design, planning, delivery, and operation of all AWS global infrastructure. In other words, we're the people who keep the cloud running. We support all AWS data centers and all of the servers, storage, networking, power, and cooling equipment that ensure our customers have continual access to the innovation they rely on. We work on the most challenging problems, with thousands of variables impacting the supply chain - and we're looking for talented people who want to help.

You'll join a diverse team of software, hardware, and network engineers, supply chain specialists, security experts, operations managers, and other vital roles. You'll collaborate with people across AWS to help us deliver the highest standards for safety and security while providing seemingly infinite capacity at the lowest possible cost for our customers. And you'll experience an inclusive culture that welcomes bold ideas and empowers you to own them to completion.

Key job responsibilities

• Design and build real-time distributed systems and algorithms that determine how CloudFront routes traffic across hundreds of edge locations
• Own data pipelines end-to-end: real-time load measurement, latency collection, and traffic placement signals from design through production operations
• Author design documents, lead technical reviews, and drive architectural decisions for your area
• Investigate routing anomalies by tracing traffic decisions through multiple system layers to root cause
• Collaborate with networking, capacity planning, and DNS teams to improve customer outcomes
• Drive operational excellence: monitoring, alerting, automation, and runbooks
• Participate in on-call rotations, responding to incidents with sound judgment
• Mentor engineers through code reviews, design guidance, and hands-on problem solving

A day in the life

You design and build the systems that decide where CloudFront routes traffic. One week you are building a new real-time pipeline that measures load across hundreds of POPs and feeds routing decisions at sub-second latency. The next you are implementing an algorithm that places prefixes onto ACE devices using latency experiment data, increasing cache utilization by double digits. You author design docs, lead reviews, ship code, and validate results in production. When routing doesn"t behave as designed, you dig in - but the core of the role is building new systems and improving existing ones, not firefighting. You work across data pipelines, routing algorithms, and distributed infrastructure at global scale.

About the team

The CloudFront Routing & Capacity Engineering team owns how CloudFront routes traffic across 400+ edge locations. We build the systems that decide which POP serves each request, balancing latency, capacity, and cost in real-time. Our stack spans DNS traffic steering, real-time load measurement pipelines, latency-based routing algorithms, and capacity planning for live events like Thursday Night Football, FIFA World Cup, and IPL. Routing decisions here execute in milliseconds and directly determine streaming quality for end users worldwide.