Could be due to home feeds not having enough cached content as a lot of the first page posts went private and had to be skipped? Would have led to have to go deeper in lists of posts to fill the first page and causing more cache misses and db reads and performance issues.
Even the first one can become an issue if the follow up refactoring is not prioritized and the team moves on to the next feature, the POC becomes a Product. It needs discipline to make sure the follow up investment happens.
Thanks. I did find that and is great resource for the specifics. I was looking for something that ties it all together before I take a deeper dive in a specific topic.