You are a Senior Replit Developer with 9+ years of experience building AI recommendation engine platforms that generate billions of personalized recommendations and improve engagement by 250% through comprehensive recommendation engine platforms and intelligent personalization optimization systems. Your expertise spans React, Node.js, PostgreSQL, ML algorithms, and AI recommendation technology. Create a comprehensive AI recommendation engine platform with recommendation engine platforms, personalization optimization, and intelligent recommendation optimization for engagement excellence and user experience optimization. Design PostgreSQL database schema for users, items, interactions, recommendations, and AI analytics with optimization for recommendation workflows and personalization tracking. Implement Replit Auth for secure recommendation access with user profiles and preference management with AI recommendation engine platform features. Build React frontend with recommendation interface, AI personalization tools, and engagement dashboard with engaging recommendation presentation and comprehensive AI personalization management capabilities. Create API endpoints for recommendation operations, AI processing, and personalization management with recommendation optimization algorithms and AI enhancement systems. Include collaborative filtering, content-based filtering, and hybrid approaches for comprehensive AI recommendation engine platform and personalization optimization. Add real-time recommendations, A/B testing, and performance tracking for enhanced engagement success and AI platform growth. Deliver complete AI recommendation platform with database schema optimized for AI recommendation data and personalization analytics, Replit Auth with secure user and preference access management, engaging React interface with AI tools and recommendation features, comprehensive API for AI operations and recommendation processing, advanced AI features including collaborative filtering and content-based filtering, and personalization platform including real-time recommendations and A/B testing. Ensure platform provides comprehensive AI recommendation engine with effective recommendation engine platforms and personalization optimization for engagement excellence and user experience optimization, offers intelligent collaborative filtering and hybrid approaches for AI accuracy and recommendation optimization, handles diverse recommendation scenarios including e-commerce and content platforms with scalable AI solutions, includes robust real-time recommendations and performance tracking for recommendation efficiency and personalization performance, maintains AI standards with recommendation accuracy and user privacy for trusted AI platform, and enhances user experience optimization and engagement excellence on AI platforms.