The top dark pattern Instagram employs is sending you internal notifications that you cannot turn off no matter of your notification settings. If you have multiple accounts it’s guaranteed you will have a little red dot sitting there making you switch to one of the accounts to clear it. I absolutely hate this and it’s going straight against their imaginary goal of being a responsible company that supports mental well…
I don't know if these patterns were pioneered by Chinese software companies, but from at least 5 years ago they were already doing this in pretty much every mobile app. Infuriatingly, my online banking app did it too, so you couldn't even just log on to check your account balance without having a half dozen pop-ups and flashing icons and weird mini-apps trying to get you to click on something almost, but not quite entirely unlike a banking product.
Nowadays I even see it on ordinary western e-commerce websites like Booking.com, or (most recently, post-redesign) the account management page of my mobile provider. I have no idea what the product managers responsible for this are thinking, because it just makes using the app an exercise in disappointment. If I click on a notification I want to get something that genuinely is important to me, not some kind of alert from a half-assed feature I never wanted in the first place.