Lol you guessed it. I actually like vertx over spring in general. the rxjava is the real problem.
That being said my biggest hurdles are always combining blocking with async code. That usually bloats my code. Examples are blocking LDAP search that needs not block the event loop.
0 - https://vertx.io/docs/apidocs/io/vertx/core/Future.html
1 - https://vertx.io/docs/apidocs/io/vertx/core/Promise.html
The most abstract I'm usually willing to get is using River [5] instead of array's map/filter/reduce.
There seems to be an absolute obsession over these libraries now though. I assume it's fueled by every frontend library pushing functional patterns. See Effect [1] for example, it's insane how much is piled on.
[2] type Fun<A, B> = (a: A) => B export const pipe = <A, B>(f: Fun<A, B>) => { return { to: <C>(g: Fun<B, C>) => pipe((arg: A) => g(f(arg))), start: () => f, }; };
[4] class TaskQueue<U = any> { private pending: Promise<any> = Promise.resolve(); add = <T,>(task: () => Promise<false extends true & U ? T : U>) => (this.pending = this.pending.then(task).catch(task)); }