In my experience the stuff that comes later usually gets harder to do right. The first few features are pretty easy - the code base is small, the rules and sta

In my experience the stuff that comes later usually gets harder to do right. The first few features are pretty easy - the code base is small, the rules and state are simple, and there aren't any major performance issues. Later on features start coming into conflict, there's more complexity to be managed, and you've used up all of your latency budget. How often do you hear that you just need to rewrite everything at that point? How often does that payoff?