I can't think of real-world examples of apps that have read path scaling problem that this tech would solve well. It would be great if the authors can catalogue

I can't think of real-world examples of apps that have read path scaling problem that this tech would solve well. It would be great if the authors can catalogue a bunch of real-world use-cases. (real-world customer case-studies would be even better). Today, machines are super huge (in terms of compute cores, memory and iops for storage and network) and a single Mysql or PostgreSQL database can do a lot of work. This makes it much much easier to build apps that don't have as many users at Internet scale – that is pretty much all enterprise apps – without resorting to distributed databases. In Internet scale consumer app domains like e-commerce/delivery or fintech where relational databases are used heavily, most queries would have strict correctness requirements and won't tolerate staleness. Also, most query-results would be highly specific to each user and won't have much cache hits. Also, apps in general are increasingly personalised and have fast changing content. In terms of technology evolution, I see people moving from single large machine databases to distributed sql databases as their use-cases scale. And as distributed sql databases mature, I expect they will get built-in capability to generate user-defined materialised views with flexibility to manage their placement w.r.t class and number of machines to compute and serve them etc.