I give a high level overview of how personalization at Netflix helps our members find titles that spark joy, as well as help stories travel across the world.

1. PERSONALIZATION
AT NETFLIX
MAKING STORIES TRAVEL
SUDEEP DAS
SENIOR RESEARCH SCIENTIST

6. BUT
ENTERTAINMENT
REMAINS LARGELY
PERSONAL

7. BUT
ENTERTAINMENT
REMAINS LARGELY
PERSONAL
In this world of abundance, personalization is the key to helping you find the content
that will spark joy for you.

9. THE NETFLIX HOMEPAGE IS DESIGNED FOR YOU

11. THE
INGREDIENTS

12. THE MAIN
INGREDIENTS
Your
viewing
history
Your
thumbs
+ My
List
adds
Members with
similar tastes
Title
details

13. Personalization 101
WHERE TO BEGIN?

14. POLL THE AUDIENCE?

15. POLL THE AUDIENCE?

16. THE FIRST
STEPS
OF
PERSONALIZATION

19. The algorithm’s first
guesses are mostly based
on POPULARITY but
gently nudged toward
YOUR
INITIAL CHOICES

20. AS YOU WATCH MORE, OUR ALGORITHMS
START TO IDENTIFY YOU WITH
INTEREST GROUPS

21. INTEREST GROUPS form organically from
millions of members viewing habits…

22. SUDEEP’S FIRST WEEK:

23. SUDEEP’S
RECOMMENDATIONS
X 0.4
X 0.3
X 0.2
X 0.1

25. AS I WATCH MORE,
MY HOMEPAGE
BECOMES
MORE
PERSONALIZED

26. IN A SHORT AMOUNT OF
TIME
PERSONALIZATION
IS ABLE TO OVERCOME
THE BIAS OF
POPULARITY

27. IN A SHORT AMOUNT OF
TIME
PERSONALIZATION
IS ABLE TO OVERCOME
THE BIAS OF
POPULARITY
BUT
HOW
MUCH
IS
TOO
MUCH?

28. Suppose you watched
several comedies
recently and your
homepage ended up
looking like this:

29. WHILE OUR
ALGOS HELP
PERSONALIZE
THEY ALSO
HELP YOU
BREAK
OUT OF YOUR
FILTER
BUBBLE
Image: Eli Pariser

30. AT 1 WEEK
SUDEEP’S
CENTRAL
INTERESTS
SUDEEP’S
EXPLORATION
ZONE

31. AT 6 MONTHS
SUDEEP’S
CENTRAL
INTERESTS
SUDEEP’S
EXPLORATION
ZONE

32. PRESENTING
THIS POSES A
CHALLENGE
MY
MIXED
BAG

33. One
Scrollable
Comedy
Row
Presenting diverse
recommendations
necessitates
ORGANIZATION
A big slate
of related
comedies

34. ROWS : A meaningful way to navigate diverse recommendations
One
Scrollable
Comedy
Row
A genre
row
A row
based on
Similarity
A
subgenre
row

35. CONSTRUCTING
THE HOME PAGE
REQUIRES
COMPLEX
ALGORITHMIC DESIGN
AND
DEEP HUMAN EXPERTISE

36. Visually-striking Nature & Ecology Documentaries
But first …
WHERE DO SUCH EXPRESSIVE
ROW HEADERS COME FROM?
Teen Supernatural TV Sci-Fi & Fantasy
Visionary Documentaries about Food

37. From Tags to Containers
Our team of in-house experts meticulously tag each title with a rich taxonomy of 200 different story data points that form the
basis of thematic containers. These containers and their descriptive row headers provide meaning. Each title may end up
belonging to many different containers.

38. HOW TO MAKE A
NETFLIX
HOMEPAGE

39. HOW TO MAKE A
NETFLIX
HOMEPAGE
1. Decide which
titles should be on
the homepage for
this member

40. HOW TO MAKE A
NETFLIX
HOMEPAGE
2. For each title
decide which of
the possible
containers/row
headers make
most sense to this
member

41. HOW TO MAKE A
NETFLIX
HOMEPAGE
3. Once a row is
formed, decide
how to rank the
titles within the
row

42. HOW TO MAKE A
NETFLIX
HOMEPAGE
4. Decide the order
of the rows so that
the most relevant
titles are placed in
the most
prominent
positions

43. HOW TO MAKE A
NETFLIX
HOMEPAGE
5. Remove
duplicates

44. HOW TO MAKE A
NETFLIX
HOMEPAGE
5. Remove
duplicates
Yes, it is complicated, but our
technology enables the
construction of a unique page for
each and every one of our members!

45. Sudeep!
WHEN YOU GIVE US FEEDBACK,
WE LISTEN

46. Sudeep!
WHEN YOU GIVE US FEEDBACK,
WE LISTEN
Thumbs signals are fed back into the
personalization algorithm, which then
adjusts your recommendations in a
meaningful way.

47. ● We want our recommendations to be accurate in that they are relevant to the
tastes of our members, but they also need to be diverse so that we can address
the spectrum of a member’s interests versus only focusing on one.
● We want to be able to highlight the depth in the catalog we have in those
interests and also the breadth we have across other areas to help our members
explore and find new interests.
● We want our recommendations to be fresh and responsive to the actions a
member takes, such as watching a show, adding to their list, or thumb up/down
OUR GUIDING PRINCIPLES

48. 148 Million Members - 190 Countries - 22 Languages
OUR ALGORITHMS ARE GLOBAL AND THEY
HELP GLOBAL STORIES BE HEARD!

49. A row from my homepage that our algorithm
formed possibly based on my interest in
Nordic Noir.

52. GLOBAL ALGORITHMS foster
GLOBAL COMMUNITIES

53. “Despite a supposed surge in nationalism across the globe, many people like to watch movies and TV
shows from other countries. “What we’re learning is that people have very diverse and eclectic tastes,
and if you provide them with the world’s stories, they will be really adventurous, and they will find
something unexpected,” Cindy Holland, Netflix’s vice president for original content, told me.”

54. Great stories come from everywhere.
Our technology enables those stories
to be heard.

55. THANK YOU