This document provides an overview of machine learning and data recommendations at Meetup.com. It discusses how Meetup uses machine learning models like logistic regression and collaborative filtering to provide topic and group recommendations to users based on their location, interests, and other attributes. Features are engineered using data like topic matches, Facebook friends, and distances between locations. Challenges include cold starts, sparsity of data, and cleaning issues. Future work may include recommendations based on clicks and impressions as well as people-to-people recommendations.
2. My Background
Software Engineer/Data Scientist
Machine learning team
At Meetup since May 2012
BS Computer Science
Information Retrieval
Data Mining
Math
Linear Algebra
Graph Theory
4. What this talk is
Super secret peek into Meetup!
Meetup recommendations examples
How we do recommendations
(model/features)
Lessons learned/whats next
5. What this talk isnt
What is a data scientist?
What is big data?
How does matrix factorization or gradient
boosted decision trees or map reduce or this
framework I hope youll use work?
6. Why Meetup data is cool
Real people meeting up
Every meetup could change someone's life
No ads, just do the best thing
Oh and 114 million rsvps by >14 million
members
2.7 million rsvps in the last 30 days
~1/second
8. Data at Meetup
User data
Site monitoring/performance
AB testing
Recommendations*
9. Everything is a recommendation
Not my phrase
Not actually true yet
Working on it
13. Topic Recommendations
New registrant
Dont know anything about you yet!
Most popular is boring/repetitive
Algorithm:
Group local meetups by topic
Select topic with most groups
Remove those groups
Repeat
18. Why Recs at Meetup are hard
Incomplete Data (topics)
Cold start
Asking user for data is hard
Going to meetups is scary
Sparsity
Location
Groups/person
Membership: 0.001%
Compare to Netflix: 1%