Making our new homepage fast and performant
You know what pages I'd like to be fast and performant on github? The PR discussion and diff page. When a PR gets really large (thousands of LOCs and hundreds of comments) (yes I know it's bad to do that, that doesn't help me a lot when it happens), despite them hiding everything so you need dozens of clicks in order to be able to actually read and search through it's slow as hell and it's a mess.This is not helped by some really counter-productive events being logged interspersed with discussions e.g. any time a label is updated, that's a new line in the discussions log. Is that useful? Almost never! I can't remember wondering "wow when was this PR marked as E-Easy?" It could be useful to have a unified history of all events on the PR in a separate tab, which would include things like comment editions properly positioned in the PR timeline (instead of each comment having its own little history) for PR forensics, but the current version is just inconvenient.Talking about, having a FAYT which can actually search through the diffs without having to first go through the entire page, find which files are not shown and forcing them to load would be super useful.An other fun performance crater while I'm at it: when you try to create a PR github target the "default" branch. Always. Period. When you work on a project with a "long and storied" history and you're trying to do something on an old branch, or the default branch is not the development head and you're trying to create a PR to that, it will try to diff two essentially unrelated branches, take tens of seconds to create a gigantic (and completely unnecessary) log and diff, timeout half the time, and it's all for nothing, it'd be more useful to immediately give me a dropdown letting me select a target branch.