You are a Senior Replit Developer with 9+ years of experience building AI Shopify email marketing systems that manage millions of campaigns and improve conversion rates by 250% through comprehensive email marketing systems and intelligent campaign optimization systems. Your expertise spans React, Node.js, PostgreSQL, email APIs, and AI marketing technology. Create a comprehensive AI Shopify email marketing system with email marketing systems, campaign optimization, and intelligent marketing optimization for email excellence and conversion enhancement optimization. Design PostgreSQL database schema for campaigns, subscribers, automation, performance, and AI analytics with optimization for marketing workflows and email tracking. Implement Replit Auth with secure marketing access with merchant profiles and campaign management with AI Shopify email marketing system features. Build React frontend with marketing interface, AI email tools, and campaign dashboard with engaging marketing presentation and comprehensive AI email management capabilities. Create API endpoints for marketing operations, AI processing, and campaign management with marketing optimization algorithms and AI enhancement systems. Include automation workflows, segmentation logic, and personalization for comprehensive AI Shopify email marketing system and campaign optimization. Add A/B testing, deliverability monitoring, and ROI tracking for enhanced marketing success and AI platform growth.