Varnion WA
A multi-tenant WhatsApp Business API gateway built on top of the open-source go-whatsapp-web-multidevice project, extended with tenant isolation, API key authentication, and round-robin device load balancing. Used internally at Varnion to power WhatsApp-based services — messaging, OTP delivery, and CRM sync — for 100+ client accounts.
Role
Fullstack Developer
Client
PT Varnion Technology Semesta
Duration
Aug 2026 - Present
Tech Stack
Overview
Varnion WA started as a fork of the open-source go-whatsapp-web-multidevice project and was rebuilt into internal infrastructure powering WhatsApp-based services for Varnion's client base — not a standalone SaaS product, but the messaging layer underneath services like automated notifications, OTP delivery, and customer support routing. Beyond the core messaging engine (whatsmeow), the project adds tenant isolation with scoped API keys, round-robin load balancing across each client's paired devices, OTP delivery through WhatsApp's own interactive message flow, Chatwoot CRM sync, and MCP (Model Context Protocol) support for AI agent integration — plus a custom admin dashboard with live connection status and device health monitoring.
Outcome
100+
client accounts served
~5
avg. devices per client
Challenges & Solutions
Retrofi Retrofitting multi-tenant isolation onto an originally single-tenant open-source base without breaking existing device-scoping guarantees.
Fullstack Developer#whatsapp-manager
Designi Designing a 4-state device connection model (connected/disconnected/unpaired/error) that stays accurate across WebSocket reconnects and QR re-pairing.
Fullstack Developer#whatsapp-manager
Key Features
- Multi-tenant Architecture with Scoped API Keys
- Round-Robin Load Balancing Across Devices
- OTP Delivery via WhatsApp Interactive Messages
- Magic Link Admin Authentication
- Chatwoot CRM Integration
- MCP (Model Context Protocol) Support for AI Agents
- Custom Admin Dashboard with Live Connection Status
Technologies Used
Frontend
Backend
Infrastructure