GitLab CEO here, I would love to know what kind of heavy is the problem you're experiencing, hard to setup? hard to upgrade? cpu/ram/disk usage? too many features?
1) This thread is about a kinda-competitor to GitLab, so maybe he was just here reading it.
2) There are monitoring services like: https://zapier.com/zapbook/zaps/675/post-message-slack-when-...
Add it on a decent reader, filter for the word "GitLab", and you're done.