[bassislife]

> But maybe monads are too exotic to provide a good example.

Nah, it's fine.

But a monad is just a part of an abstraction. Which also means that they have been used without that specific denomination for ages.

The use of Category theory just allows to think about things out-of-context but it is not necessary nor evident that it "always" leads to interesting results for the everyday programmer.

It is like the difference between applied and pure mathematics.

The concept of a monad in haskell was introduced to solve a specific problem though, if I remember well. And it was not uncontroversial. But people who know better could chime in.

[gravypod]

Have there been developments of similar or better constructs accidentally/naturally outside of the efforts put forward by PLT?

If I wanted to see what was being said by the field, are there any seminal works to 'ingest'?

[bassislife]

For category theory, I don't think so. But if we take tensor algebra, of course, in physics, especially quantum mechanics .The thing is, you could approach the same physical problem at different levels of abstraction and would therefore use either or. For the study of manifolds, people generally tend to favor tensorial analysis. But some results could be found within the framework of category theory.

In terms of seminal work, I admit I am quite ignorant. I would check with SIAM.