> Traditional programming languages and imperative thinking don't lend themselves to writing state machines

That's probably not the problem - imperative development can start off from a level of complexity where state machines don't look relevant.

Six weeks down the line, the whole codebase has overtaken the complexity of a state machine, though each of the development bugs were simple fixes to the original branching code.

The standard web-app wizard is where I've run into this again and again.

Every web-app is stateful enough to maintain DB state sync'd & ticking over from a user-click, which makes it really easy to work out whether all clicks go somewhere useful.

However this makes sense only when you have around 7+ states and transitions between them (particularly the "go back" one).

Until then, the regular if/else branch scenarios work out just fine ... but then when you're near the 20-30 state range, it all falls apart.