I don't think it's the code necessarily. It's the feature creep. It used to be that we just supported monitors - now it's touchscreens, tablets, watches, keyboards, mouse. It's LCD screens, plasma, TV, and so on.

I find that code become exponentially more costly the more features you add in, because of the number of architectural layers you have to add on. And if you haven't planned for that, well, now you have to deal with the pain of adding another architectural layer.

HN is likely in the sweet spot of good architecture, but it also means that it's not supporting things like infinite scrolling and reddit-like awards.