Besides being able to submit and discuss postmortems, posts are organized by tags that you can subscribe to so you can keep up to date about new postmortems you care about (either through a custom feed or a weekly email digest).
You can also submit your own postmortems as formatted text directly on the site, but admittedly this feature is pretty basic right now (I just started adding a few templates but would love feedback here and ideas for other templates).
I know there are already a few large postmortem lists out there that are variously maintained and HN itself already does a really good job of capturing discussion about postmortems for large enough incidents the moment they happen, but the lists tend to get outdated and lack discussion, and the HN stories get lost after a day or so, so I thought creating a separate place dedicated to these documents might be useful to others as more and more companies participate in the practice.
This is very much a v1 passion project (inspired from the feedback on talks I’ve given about our startup Kintaba) so would love feedback or ideas!
 https://github.com/danluu/post-mortems - a commonly referenced existing list