You just check the comments feed occasionally, and make sure you follow it back far enough until you've found a comment you've previously seen (or a time prior to the last seen comment). Of those comments, if any are for users that have requested notification, shoot off an email to their supplied notification email address with the relevant info.
It's really not that complicated, and a great starter/hobby project. I imagine the only reason there wasn't a replacement out sooner for the prior site that stopped working is that a lot of us weren't really aware it had stopped, or weren't aware it was dead and not suspended (is it?), or hadn't yet gotten off our buts to make a replacement once we determined the prior site was gone.
It's the kind of small scope and easily defined project that's great for learning a new language.
Come on now. I'm sure the commenter knew you could search the subscriber list when new comments come in. I think the real interest was in how Grossman may have optimized it for CPU or memory efficiency. I was curious myself given it's easier to keep sites like this up if they take almost no resources to run. Some low-power, disposable box or extra CPU cycles on an existing server.
"It's the kind of small scope and easily defined project that's great for learning a new language."
I totally agree with that. Matter of fact, I was planning on implementing that exact project to learn Rust or Go. :) Might still do it as it remains a good learning experience, esp for stuff you use 80% of the time.
> Come on now. I'm sure the commenter knew you could search the subscriber list when new comments come in.
Well, that may have been obvious to you, but I didn't want to assume anything about the asker, and while it appears the majority of users here are developers at times, there are still people that frequent that have little or no practical software engineering experience. In any case, it's easy to overlook features of a site you never or rarely use. I've clicked on the comments feed maybe 3-4 times in a few years, if I hadn't thought about this issue previously (as obviously you have as well), I might or might not have immediately thought about the comments link, and how it's really a feed.
