I feel the same pay-off - but arrived at that point via Clojure. Immutable-first, aim for purity, ability to drop out of it when necessary. As stringent as you

I feel the same pay-off - but arrived at that point via Clojure. Immutable-first, aim for purity, ability to drop out of it when necessary. As stringent as you need it to be (static vs. dynamic types vs. specs), as flexible as you want it to be.