I am not sure whether Pulsar would anywhere achieve the speed / throughout of a truly concurrent system like JVM, Go, Haskell, and Erlang. I don't see benchmarks posted on Pulsar's website, but I came across this discussion [1] where aphyr and KiranDave discuss about why Clojure/Erlang's model of explicit concurrency (which enabled parallelism) is superior to NodeJs' (implicit concurrency via libuv, and multi-process parallelism via clusters).
From reading the "design" section on the website, to me it looks like Pulsar is an attempt to replicate NodeJs (?) and by extension cannot compete with languages with truly concurrent runtimes?
Pulsar can be configured to use either processes or threads. If you use processes, you pay the IPC penalty, just like NodeJS does. If you use threads, you pay the GIL penalty.
So yeah, it won't be as fast as BEAM or the JVM either way.
From reading the "design" section on the website, to me it looks like Pulsar is an attempt to replicate NodeJs (?) and by extension cannot compete with languages with truly concurrent runtimes?
[1] https://news.ycombinator.com/item?id=4306241