Mutable State is to Software as Moving Parts are to Hardware

Photo by Bill Oxford on Unsplash

..in that, there are categories of problems that can’t really be solved without it, but as soon as you introduce it, your whole system becomes just a bit more fragile. You get that whole “I can’t stop it right now, it’s in the middle of something”-concern to worry about.

Additionally, there are a problems that you can solve without it, but where the immutable solution will perform poorly. In that case, it is probably best to start out with the immutable solution and make the switch no sooner than the day you realize that you can’t postpone it any more.