How's Linear so fast?

https://performance.dev/how-is-linear-so-fast-a-technical-breakdown

• They use a sync engine such that user changes are optimistically applied
• They carefully load only the JS/CSS that is required at the start, and preload as much as possible
• They chunk the application very granularly, and use a service worker to preload chunks

This made me interested in how their sync engine works, so I'm watching this talk:

• I've previously mentioned electric, which implements a sync engine with CRDTs
• I've previously mentioned Replicache in Offline-First Landscape and Real-time Collaboration with replicache and fly-replay
  • a news.yc commenter points to this doc about how replicache works
  • zero, who I guess are the company that supports replicache, have this doc which points to alternatives to it
• news.yc points to this reverse-engineering of the linear sync engine