Full-Stack Integration Expert: Multi-Platform OAuth & Automated Analytics Sync (Supabase)

Overview:
I am building a creator-management platform (Insytli) and need a robust, production-ready backend integration for Facebook, Instagram, TikTok, and YouTube. The goal is to allow creators to authenticate their accounts and have their performance data automatically synced to my database.

Technical Stack Requirements:
- Backend: Node.js / TypeScript (strictly server-side for security).
- Database/Auth: Supabase (PostgreSQL).
- APIs: Official Graph/Marketing APIs for Meta, TikTok for Developers, and YouTube Data API v3.

Detailed Scope of Work:
- Secure OAuth System: Implement official OAuth 2.0 flows.
- Access tokens must be encrypted at rest in Supabase and handled via a secure server-side token refresh logic.

Granular Data Ingestion:
- Account-Level Metrics: Total followers, daily reach, total impressions, and profile views.
- Post/Media-Level Metrics: Detailed stats for individual posts, videos, and Reels (Likes, Comments, Shares, Saves, Views, and Engagement Rate).
- 90-Day Backfill: Upon the first successful connection, the system must perform a one-time backfill of the last 90 days of historical data.
- Automated Cron Jobs: Set up a 24h scheduled sync with a robust retry policy (exponential backoff) to handle API rate limits or downtime.
- Normalized Database Schema: Design clean PostgreSQL tables in Supabase that consolidate metrics from different platforms into a unified structure for easy frontend consumption. Use RLS (Row Level Security) to ensure data privacy.

Acceptance Criteria:
- Fully functional OAuth login for all 4 platforms.
- Background sync logs (Success/Failure) stored in a dedicated table.
- Data must be retrieved for both the overall account and individual media items.
- Complete source code, unit tests, and comprehensive setup documentation delivered via Git.

Bonus Question for Applicants:
Please briefly explain your experience with Meta Business Verification and how you ensure apps stay compliant during the App Review process to move from Development to Production mode.