Erlang and Elixir (and likely any BEAM language) give you:
- 99% transparent parallelism and concurrency. I can’t stress enough how important this is and how I spent 15 years of my career trying to emulate this trait in at least 5 other languages (and failed like everyone else who tried the same).
- Lag-less operation: spawn 50_000 tasks and the runtime will give them all a fair treatment for as much as the hardware allows.
- Pre-emptive scheduling. No single task can slow down the others.
- Ability to structure your software as a tree of tasks and supervisors, with the supervisors restarting tasks if they fail. The so-called fault tolerance. This is EXTREMELY underrated and people usually come looking for this in Erlang and Elixir after suffering in other ecosystems for a long time. I haven’t met a single new programmer who is able to appreciate how much of a productivity boost and a reducer of stress this feature is but oh well, what can you do.
- Elixir-specific: macros. Basically code generators at compile time. Another vastly underrated productivity booster.
While other 30-year old languages like OCaml are still struggling to even produce a working multithreaded runtime (hope it doesn’t take them another decade to make an actor runtime!), and others like Rust are just now laying the foundations of a solid asynchronous multicore runtime (and Go never being that impressive in that regard to begin with), Erlang has been enjoying a multicore pre-emptive runtime for 20+ years, long before mainstream multicore CPUs even existed.
Many programmers underestimate these aspects, to their peril.
Elixir is one of the secret weapons in the programming area.
