Its strengths lie in its concurrency, simple message passing, distributed design, and robust VM. The really interesting part is message passing and easy peasy

Its strengths lie in its concurrency, simple message passing, distributed design, and robust VM. The really interesting part is message passing and easy peasy baked in communication that allows to to send messages to other erlang nodes. So building applications that talk to each other over networks is just a normal function of the language and not a higher level dependency such as a library. The concurrency is also pretty neat as erlang treats all threads of execution as an erlang process. So merging that with the distribution and simple message passing you can easily build stuff that scales without much external tooling. It's almost an OS unto itself. There are two interesting IoT systems which use it to such length such as GRiSP which is erlang beam ported to bare metal using RTEMS and Nerves which runs beam directly on top of a Linux kernel making beam the serspace.