Do you know big startups workflows about users retention?

I'm searching the workflows about users retention in big startup like deliveroo, netflix, uber/uber eat, runtastic, etc..

Do you know a website or personally the workflows of these websites ?

I started a list, I'd like to do something participative, like an open source github project to contribute, for example with runtastic by adidas :

if the user has activated his account :

if the user played sports during the week :

send user’s stat review by email of the past week every monday or tuesday every week
send user’s records by email like "fastest mile, best sport and top duration" on wednesday

if the user has not played sports for 2 weeks :

if the user has not played sports for 1 month :

send an email to user about how sport is important in your life every month as long as the user has not deleted his account

If you want to participate and study on this open source project, add comment and PM me !