> Unlike in (say) Python, where annotations are effectively functions wrapping the function they annotate, in java they're more akin to a customisable preprocessor.

I find that Python decorators can do as much magic as an annotation processor - due to the dynamism of Python. Annotation processors, in most cases, produce a new class based on annotations on existing class / interface. The injection of that class is done by the DI container (unless it's a standalone annotation processor like mapstruct).

> And using any modern framework relies on these a lot.

To be fair to language designers, it's hard to avoid code generators. And they're a compelling thing compared to building proxy objects / DI / decorator / dataclass etc.. kind of functionality in language and getting it wrong.

> ... then you have to dig into source to figure out

Agree. It's not a "boring technology" yet.

> For all it's called micronaut, the produced packages are pretty huge.

How huge? And jlink or graal vm? Just curious.

> A lot of this seems to be down to hibernate,

With micronaut atleast, I remember using Micronaut Data JDBC. Anything is better than hibernate.

> In general I think that serverless is such a different paradigm from a long-running server.

Agreed.