Neat design! The coolest insight, IMO:

> We’ve learned from building and operating large-scale systems for nearly two decades that coordination and locking get in the way of scalability, latency, and reliability for systems of all sizes. In fact, avoiding unnecessary coordination is the fundamental enabler for scaling in distributed systems

I hope there is a follow-up since the points the author only glossed over are important to understanding the architecture and trade-offs. I would like to know about the cross-adjudicator coordination protocol and how the journal works.

From the information available, it seems that DSQL should be pretty fast as long as you keep writes local. Once you add active-active replication and start writing to the same key in different regions the coordination costs should slow the system down significantly (or not - but if that is the case I want to know how they managed to do it).