A notable example of a large-scale app built with a very similar architecture is ATproto/Bluesky[1].

"ATProto for Distributed Systems Engineers" describes how updates from the users end up in their own small databases (called PDS) and then a replicated log. What we traditionally think of as an API server (called a view server in ATProto) is simply one among the many materializations of this log.

I personally find this model of thinking about dataflow in large-scale apps pretty neat and easy to understand. The parallels are unsurprising since both the Restate blog and ATProto docs link to the same blog post by Martin Kleppmann.

This arch seems to be working really well for Bluesky, as they clearly aced through multiple 10x events very recently.

[1]: https://atproto.com/articles/atproto-for-distsys-engineers