(Photo taken during my visit to Amazon Spheres, with The Westin Building visible on the far left. Image source: Ernest.)
✳️ tl;dr
- I’ve passed by this building countless times while attending meetings or exploring coffee shops and restaurants in downtown Seattle, never realizing its significance.
- The Westin Building Exchange is a major telecommunications hub facility located in downtown Seattle, Washington. 1
- The building was constructed in 1981 (around the same era as me XDD),
- Originally named The Westin Building, it served as the headquarters for the Seattle-based Westin Hotel chain.
- It also houses the Seattle Internet Exchange (SIX) and the Pacific Northwest Gigapop Pacific Wave Exchange.
- Since 2019 or earlier, heat generated by the building’s data center has been piped to Amazon’s Doppler building next door, providing heating for Doppler and several other Amazon buildings.
- Amazon estimates that over the system’s expected 25-year lifespan, it will save 80 million kilowatt-hours of electricity, equivalent to 65 million pounds of coal.
- The trigger: I came across The Verge’s report on Microsoft’s plan to migrate GitHub entirely to Azure, which made me curious about its infrastructure before the acquisition. 2
- GitHub was acquired by Microsoft in 2018. So I went back to check the situation in 2017.
- GitHub’s blog once described: “Those facilities don’t store customer data, rather they’re focused on internet and backbone connectivity as well as direct connect and private network interfaces to Amazon Web Services.” 3
- GitHub is now (2025) undergoing what may be its largest infrastructure migration ever, planning to move the entire platform from self-owned data centers to Azure within 24 months.
- The core driver of this migration is the explosive growth of AI workloads: GitHub Copilot generates millions of code suggestions daily, consuming massive computing capacity, and the existing data centers have reached their physical expansion limits. (There’s always an official narrative for the public—take it with a grain of salt) (There’s a kind of cold where grandma thinks you’re cold. There’s a kind of migration where ____ tells you to migrate?!)
- Migration strategy: Most work needs to be completed within 12 months (because new and old systems need to run in parallel for at least 6 months), GitHub has asked teams to delay feature development and prioritize infrastructure migration.
- In 2024, GitHub experienced 119 incidents, including 26 major outages, with an average resolution time of about 106 minutes. 4
- Curious to see how it performs after the move.
- For those of you tech managers using GitHub, I’m curious—what’s your take? Will this trigger any preparations on your end?
