[coverup]

> This mentality leads to systems that are a mess of callbacks, don't scale, and practically impossible to maintain.

Why would it? I can put the same types of abstractions into my application layer in the form of a common library. Only difference is they can be a lot fewer and simpler because they only need to meet my exact requirements.

I often do make the same argument about SQL databases in cases where RDBMSs are not an appropriate tool for the job. In the case I mentioned, where I'm using it as a shared datastore that supports ACID transactions with concurrent access, I find Postgres (and many others, including many NoSQL stores) to be suitably placed in the abstraction spectrum to be worth using rather than rolling my own solution.

[mfateev]

I agree in principle that there is not single tool for every possible situation.

At the same time I witnessed hundreds of cases when developers spent inappropriate amount of time developing "abstractions into application layer" instead of the business logic.