The lighter let-it-crash is a circuit breaker. This is done quite frequently in the JVM world because .. well the JVM has a really shitty startup time.. even restarting threadpools can be expensive.

I get the whole let-it-crash but I really would like more tools on feedback control and backpressure handling (ie whats the right amount threads to allocate and how many failures/timeouts should you allow etc...). Even monitoring is a pain (ie too many alarms). I don't know if erlang provides libraries for this but its a hard problem (see https://github.com/Netflix/Hystrix/issues/131).

Sadly, they are not mentioned much in books or other documentation, despite being a potentially extremely useful piece of infrastructure for some kinds of projects.