WhatsApp Marketing & Bulk Messaging System

We already have OTP and transaction templates working through WhatsApp Manager, and now we want to extend this into a marketing/social messaging utility that can handle bulk sends with personalization. Let me lay out a complete scope of work for such a system:
Functional Scope
1. Template Management
• Fetch approved templates directly from Meta WhatsApp Manager API.
• Display available templates (Marketing, Utility, Authentication).
• Support text + image templates (header image, body text, footer, CTA buttons).
2. Data Upload & Processing
• Upload Excel/CSV file containing:
o Customer Name
o Phone Number (with country code)
o Optional fields (email, city, etc.)
• Validate numbers (format, duplicates, opt in compliance).
• Map Excel columns to template variables (e.g., {{1}} = Name).
3. Message Personalization
• Insert dynamic values from sheet into template placeholders.
• Example: Template: “Hello {{1}}, enjoy 20% off today!” Excel row: Name = “Rachana” → Message: “Hello Rachana, enjoy 20% off today!”
4. Media Handling
• Allow upload of images/videos linked to template headers.
• Store media in Meta’s Media Library (via API).
• Associate media IDs with template before sending.
5. Bulk Sending Utility
• Integrate with WhatsApp Cloud API (via business.facebook.com).
• Queue messages for bulk sending (to avoid rate limits).
• Track delivery status (sent, delivered, read).
• Retry failed sends (network/API errors).
6. Reporting & Insights
• Dashboard showing:
o Total messages sent
o Delivered vs. failed
o Open/read rates
o Template quality rating (Meta assigns High/Medium/Low)
7. Compliance & Opt Out
• Ensure only opted in users receive marketing messages.
• Add opt out CTA (e.g., “Reply STOP to unsubscribe”).
• Maintain suppression list (don’t send to blocked/unsubscribed numbers).
• Take care for rules and regulations of whatsapp manager to avoid black listing
Technical Scope
• Frontend Utility: Web dashboard (React/Angular) for uploading Excel, selecting template, previewing personalized messages.
• Backend Service: Node.js/Python service to:
o Parse Excel
o Call Meta WhatsApp Cloud API
o Handle media uploads
o Manage bulk send queue
• Database: Store customer list, opt out list, send logs.
• Integration: Meta Business API (Graph API endpoints for templates, media, and messages).
• Security: API keys stored securely, GDPR/DPDP compliance for customer data.
Workflow Example
1. Upload Excel with 500 customer names/numbers.
2. Utility fetches approved templates from WhatsApp Manager.
3. Select “Festival Offer” template (Hindi + English, with image).
4. Map {{1}} → Name column.
5. Upload offer banner image → stored in Meta Media Library.
6. Utility sends personalized messages in batches (e.g., 50/minute).
7. Dashboard shows delivery/read stats.
8.