3. Contents
1. Challenges in Music Recommendation
2. System Overview
3. User Representation
4. Context Awareness
5. Realtime Dynamic Re-Ranking
6. Future Plan
5. Challenges in Music Recommendation
Duration
Usually less than 5 min.
Scalability
Over 30 million target items
Consumption Behavior
Sequential, Passively consumed
Emotion
Affect musical preference
Listening Context
Time, Place, Occasion
6. vs
• Voice Interface
• Hands-free, Eyes-free
• Multiple User
• Multiple Preference
• Multiple Usability
• T.P.O
Challenges in NUGU Music Recommendation
7. 3 Contents Provider*
30 million tracks
1.2 million Active Target User
Music Recommendation @ NUGU
* FLO, Melon, Bugs
9. Candidate Logic #1
Candidate Logic #2
Candidate Logic #N
…
Preference
Re-ranking
T.P.O
Re-ranking
Realtime
Re-ranking
1st-stage
2nd-stage
Itemmetadata
UserLog
Track
Representation
Model
Track
T.P.O Model
M.P.
User Model
K.P.I
Optimization
Model
User Profile
(Demographic, Genre Pref., Artist Pref., Track Pref., etc.)
ContentProvider
Recommendation
User Feedback
Two-stage Cascaded Hybrid Architecture
High Recall High Precision KPI Optimization
10. Candidate Generation (1st stage)
Collaborative Filtering
based
Contents
based
Profile
based
Heuristic
• BPR
• Item KNN
• WRMF
• Neural CF
• …
• Audio Signal
• Session Song2Vec
• TPO Rec.
• …
• M.P UM ANN
• Meta. Pref.
• …
• Popularity
• Recency / Frequency
• …
• 4 main candidate generation logics
• 10+ logic variations
• 100 candidate each
• Recall focused optimization
11. Re-ranking (2nd stage)
Candidate Track List
Final Recommendation
User Preference
Seasonality
Short-term Interest
Static
Re-Ranking
Layer
Playtime focused LTR
T.P.O Model
RL-based Dynamic Re-ranking
~1000s
50
12. First-time User Light User Active User
Definition New User, No Interaction
Few Interaction
No Consume Pattern
Active Interaction
Pattern Captured
Approach
User Profile
Popularity
Acoustic CBF, User Profile
, CF (Hybridization)
N/A
Exploration Exploitation
Cold Starter Handling
24. Realtime User Feedback Loop
• Better Recommendation
• Exploration & Exploitation a Search Space
• Multi-Armed Bandit System
• Gradually drives more traffic towards the better
items (i.e. Song)
• Faster and more Efficient process to get the best
possible items