Personalizer
Azure AI Personalizer was a reinforcement learning service that helped applications choose the best content or actions to show users based on their real-time behavior and context. The service learned from user feedback to optimize recommendations over time.What Was Personalizer?
Personalizer used reinforcement learning to:- Rank actions: Determine the best action for a given context
- Learn from feedback: Improve decisions based on rewards
- Personalize at scale: Optimize for all users collectively
- Adapt in real-time: Update models continuously
This documentation is provided for historical reference and migration planning only.
How It Worked
Personalizer used two primary APIs:Rank API
Determine the best action for current context:Reward API
Provide feedback on the recommendation:Key Concepts
Actions
Content items or choices to rank:- ID: Unique identifier for the action
- Features: Characteristics describing the action
- Example: Articles, products, ads, recommendations
Context
Information about the current situation:- User features: Demographics, preferences, history
- Environment features: Time, device, location
- Session features: Page type, previous actions
Rewards
Feedback indicating outcome quality:- Range: 0 (worst) to 1 (best)
- Timing: Real-time or delayed
- Meaning: Defined by your business objectives
| User Behavior | Reward Score | Reasoning |
|---|---|---|
| Clicked and purchased | 1.0 | Best outcome |
| Clicked, viewed 90%+ | 0.8 | Strong engagement |
| Clicked, viewed 30%+ | 0.5 | Moderate interest |
| Clicked, bounced quickly | 0.2 | Poor match |
| Did not click | 0.0 | Not relevant |
Learning Modes
Apprentice Mode
Safe training mode for new models:- Learn from your existing logic
- No impact on user experience
- Validate features and configuration
- Returns your baseline action
- Build confidence before going live
Online Mode
Production mode with active learning:- Returns best predicted action
- Explores alternative actions
- Learns from all feedback
- Continuously improves
- Optimizes for reward maximization
Use Cases
Personalizer was used for:Content Personalization
- News article recommendations
- Video suggestions
- Product recommendations
- Ad placement optimization
- Email content selection
User Experience
- Homepage layout personalization
- Feature highlighting
- Navigation customization
- Search result ranking
- Notification timing
E-commerce
- Product recommendations
- Promotional offers
- Pricing strategies
- Bundle suggestions
- Upsell opportunities
Communication
- Push notification timing
- Email subject lines
- Message content selection
- Communication channel choice
Features and Configuration
Feature Engineering
Design effective features:- Categorical: Device type, location, category
- Numerical: Price, rating, popularity
- Boolean: Is premium, has discount, in stock
- Text: Tags, keywords (as categorical)
- Use 5-50 features per action/context
- Include diverse feature types
- Avoid highly correlated features
- Update features as they change
- Test feature importance
Model Configuration
- Update frequency: How often model trains
- Exploration percentage: Random action probability
- Reward wait time: Delay for reward signal
- Default reward: Reward when none provided
Evaluation
- Offline evaluation: Compare strategies on historical data
- Online evaluation: A/B test in production
- Counterfactual evaluation: Estimate alternative policies
Migration Alternatives
With Personalizer retired, consider:Azure AI Solutions
- Azure OpenAI: For LLM-based recommendations
- Azure Machine Learning: Custom recommendation models
- Azure Applied AI: Pre-built AI solutions
Recommendation Systems
- Collaborative filtering: User-item matrix factorization
- Content-based filtering: Feature-based matching
- Hybrid approaches: Combine multiple techniques
Third-Party Services
- Amazon Personalize
- Google Recommendations AI
- Algolia Recommend
- Custom ML solutions
Best Practices (Historical)
For reference, best practices included:Data Requirements
- Minimum 1,000 events per day for learning
- Consistent feature schema
- Quality reward signals
- Sufficient action variety (50 max recommended)
Feature Design
- Use relevant, non-redundant features
- Include both action and context features
- Update features when they change
- Test feature importance with evaluations
Reward Function
- Align with business objectives
- Provide timely feedback
- Use consistent scale (0-1)
- Consider delayed rewards for complex goals
Testing
- Start in Apprentice mode
- Run offline evaluations
- A/B test before full deployment
- Monitor metrics continuously
SDK Support (Historical)
Personalizer supported:Python
C#
JavaScript
Java
Maven package available
Migration Guidance
Resources
Support
For existing Personalizer implementations:- Review retirement timeline and deadlines
- Plan migration strategy
- Export critical data
- Implement alternative solutions
- Contact Azure support for migration assistance