What parameters will you take into consideration while designing a recommendation engine for Netflix?

Netflix is an online on demand streaming platform. Its mission is to provide entertainment to its users.

The goal of designing a recommendation engine is :

1.       1. To increase the average viewing time per user by recommending relevant and entertaining content.

2. To decrease the average time spend per user in browsing which leads to frustration and disinterest.

Keeping the above 2 goals in mind, my approach would be to personalize the recommendations by creating user personas based on their demographics such as

-       location, age, gender, weather, day of the week, time of the day, content watched in recent past, content browsed in recent past, device used, content added to the watch list, shows based on genres liked/watched, actors liked/watched, languages preferred, average time spent per day watching Netflix,  average duration of shows watched, in case multiple users are sharing an account then what are the fellow users watching, watching habit – binge watcher, weekend watchers etc, keywords searched, previews watched, shows likes/reviewed, correlation between shows ex: user A watched shows 1 and 2 then user B who watched show 1 might also prefer watching show 2, Clicks per impression shown after the keyword search

Sample use case:

Persona 1: Young Millenial - A single male 25 to 27 yrs old living in NYC , earns 60k to 80k, loves watching latest releases (movies & shows) in action and drama genres on Netflix. Weekend Netflix watcher.

He turns on Netflix on a Friday evening, the preview shows the new thriller movie released today, he is also shown a list of shows which he has already been watching, there is a notification from a close friend asking him to check out the latest Jack Ryan movie that was added to Netflix this week.

Persona 2: Busy working woman – A woman 35 to 40 yrs old living in San Jose, CA, earns 120K to 150K, late night show watcher, interested in historical dramas, mystery and sci-fi shows. Shares account with partner interested in cooking shows and home grooming shows

She turns on Netflix on a Thursday night at around 9:30, a preview of the latest sci-fi show in shown to her, followed by a list of shows she has been watching along with a prompt for the arrival of new season of her favorite historical drama show which she had been awaiting for a long time. She is also shown a new recommendation for a baking show based on her watch history.