I think "shallow" is being a bit uncharitable. The book here doesn't dive into ditributed systems theory very deeply but it gives a very rich overview of real i

I think "shallow" is being a bit uncharitable. The book here doesn't dive into ditributed systems theory very deeply but it gives a very rich overview of real industry tools used over the past few decades with plenty of context around why technologies are being used or discarded. They go into code examples of things like CRDTs so its not like its just prose. One thing that feels off to me as a backend engineer that deals with distributed systems in practice is no treatment (AFAICT) of containers/virtual machines and how tools like kubernetes are providing the primitives that the distributed languages of the past provided. In general I think chapter 4 doesn't have a cohesive narrative on its treatment of languages for distributed computation. I know this is messy topic but I think more could be done to tie things to current art. If I were to make a prediction, there's general trend towards protocols (mostly network level above layer 4) being the actual thing of interest for distributed computation, not single language runtimes. Wire-compatible DBs like AWS aurora and MySQL are an example, but also I think things like container orchestator's liveness and readiness checks over HTTP. As more primitives rally around the same core concepts, I think the general trend will be to go from conceptual similarity, to client library compatability (e.g. identical interfaces a la OpenTracing <> Lightstep, Jaeger) and eventually wire/protocol compatibility. Language runtimes are too much of a moving target as there are other pressures at play (community, tooling, typing, yes even syntax) that go into language choices over a decade.