Especially when there's a fancy fully-real-time API provided for free by firebase. Not that it's the most efficient way to query all the top stories, but there's plenty that can be done with it.
It works pretty well, but there are still some "issues" you need to deal with:
- Items for users with a delay configured get posted to the API before their content is made available (if you go to the story id on HN proper, there's a * placeholder)
- The odd item will come back as `null` from the API for a while
As long as you deal going from not having content for an item to having content in an update, the API usually corrects itself eventually.
Here are live feeds of new stories and comments from the Firebase API in the client I wrote when it was announced: