Edit - In the wild, a 503 usually means that the person who built out the site did not do a very good job of estimating traffic. An empty response can return 503 if the server is overwhelmed with connections.
In other words, a 503 more likely than not has nothing to do with code and has everything to do with provisioning enough resources for the amount of traffic received. Unfortunately, that's a tough thing to get right, particularly when you land on the front page of Hacker News during extremely busy times.
My comment was just (probably ugly) joke attempt. Though, you was right - I didn't understand 503 fully, and then I became interested after your hint and googled for it.
Now I know, that it can be easily a cause (out of the many) when owner simply "suspended" site for a while, and fixing stuff.
Edit - In the wild, a 503 usually means that the person who built out the site did not do a very good job of estimating traffic. An empty response can return 503 if the server is overwhelmed with connections.
In other words, a 503 more likely than not has nothing to do with code and has everything to do with provisioning enough resources for the amount of traffic received. Unfortunately, that's a tough thing to get right, particularly when you land on the front page of Hacker News during extremely busy times.