From the outside, Bluesky may seem like a Twitter clone. But anyone who’s close to the technology — and the team — knows that they’re building something much deeper: they’re rethinking the internet’s architecture to create a more flexible, user-centric web.

Bluesky’s CTO Paul Frazee is the perfect person to explain all this, as he’s fantastic at tying technical concepts to their practical application and wider impact. In this interview with Mike McCue, recorded live at the Fediverse House at SXSW 2025, Frazee unpacks Bluesky’s first principles, what makes AT Protocol different from ActivityPub, why identity portability is a radical shift, and how decentralization could lead to more humane social spaces.

Other highlights include:

Bluesky's growth spike and architecture first principles
The challenges of bridging between federated networks
What it means to build for composability
How stackable moderation works
Paul's take on full federation
Why this is a greenfield moment for developers
Bridging cultural echo chambers

Mentioned in this episode:

Beaker Browser post-mortem

🔎 You can find Paul on Bluesky @pfrazee.com.

✚ You can connect with Mike McCue all across the social web, including on Bluesky @mmccue.bsky.social.

🌊 Catch the wave! Surf the social web and create your own custom feeds at surf.social, a new beta from the people at Flipboard: https://about.surf.social/

Creating an ATmosphere of Possibility, with Bluesky’s Paul Frazee