Architecture case study
WhatsApp SaaS Platform
Multi-tenant messaging automation — templates, CRM sync, and workflow bots on WhatsApp Business API.
WhatsAppSaaSAutomation
Problem
Businesses needed WhatsApp automation (support, OTP, campaigns) with tenant isolation, billing hooks, and CRM integrations — not one-off scripts.
Architecture approach
Tenant-scoped API layer over Meta Cloud API, with workflow engine for bot logic and webhook normalisation into a unified conversation model.
Key challenges
- Per-tenant template and phone number management
- Webhook signature validation and idempotency
- CRM sync without blocking message send path
Scalability decisions
- Row-level tenant isolation in PostgreSQL
- Async CRM sync via event bus
- Rate-limit aware send scheduler per tenant
Outcome
Operators run automated WhatsApp workflows with audit history — new tenants onboard without infrastructure changes.
Multi-tenant
SaaS isolation
Tech stack
Next.jsNode.jsPostgreSQLRedisWhatsApp Business APIAzure
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