What programming/technical projects have you been working on?

For my hobby project https://linklonk.com (a link aggregator with a trust system) I added a notification mechanism for comments - you can subscribe to get replies by email. You can subscribe at any level of the comment tree. And you can mute any subtree. If you would like to try it out, feel free to post test comments under this post where I announced the feature: https://linklonk.com/item/396040801387544576

I know, it is a complete overkill because there are so few comments posted, but it's been an interesting exercise. One challenge was to calculate whether a given user should be notified of a new reply. Each user can have multiple subscriptions and multiple mutes in the same tree, so you need to find the closest subscription/mute object to the new reply.

Another challenge is how to show it in the UI that is understandable and not too overwhelming. For now there one of the four button options:

• "Subscribe" - for nodes that you are not subscribed to yet.
• "Subscribed" - for nodes that you are explicitly subscribed to. Clicking it removes the subscription.
• "Mute" - for nodes who have a parent that you are subscribed to. That is, you are transitively subscribed to it and can put a mute on it.
• "Muted" - for nodes that you muted. Clicking unmutes this node.

Please let me know if you have any suggestions. Is any other tree-based system have something like it? Tildes/HN don't seem to have it. Reddit has "Follow" and "Followed" state (which are similar to "Subscribe"/"Subscribed"). Though I'm not sure if "Follow" applies to the whole subtree or only to direct replies.