Senior Backend Engineer. WhatsApp Business API + AI Message Routing System

We operate a SaaS business and are looking to build a lightweight internal operations tool that helps route incoming WhatsApp customer messages to the correct team members. This is NOT a chatbot project. This is NOT a customer-facing SaaS platform. This is an internal workflow automation project designed to improve team efficiency. Project Goal Today all incoming customer messages arrive in a shared WhatsApp Business environment and are visible to multiple team members. Examples: - Sales - Technical Support - Billing - Management As a result, multiple people often read the same conversation even when only one person needs to handle it. We want to build a simple system that: 1. Receives incoming WhatsApp messages 2. Uses AI to classify message intent 3. Determines which department should handle the message 4. Sends a notification to the responsible person or team 5. Generates a suggested reply Examples Example 1: Customer: "Can you send me a copy of my invoice?" System: - Category: Billing - Confidence: High - Suggested owner: Billing Team - Suggested reply generated - Notification sent to Billing Example 2: Customer: "My call recordings stopped working." System: - Category: Technical Support - Suggested owner: Support Team - Suggested reply generated - Notification sent to Support Scope (Version 1) Incoming WhatsApp message processing AI classification into categories: - Sales - Technical Support - Billing - Management - Other Department assignment Slack and/or Telegram notifications Suggested AI response generation Basic logging Requirements Must Have: - Strong backend development experience - WhatsApp Business API experience - REST API integration experience - OpenAI or Anthropic API experience - Slack API and/or Telegram Bot API experience - Experience working with webhooks Nice To Have: - Event-driven systems - Queue processing - CRM integrations - SaaS product experience - Customer support workflow systems Important We are intentionally keeping Version 1 very small. We are NOT looking for: - frontend development - mobile development - chatbot platforms - no-code automation tools - complex dashboards The primary deliverable is a working backend service that routes incoming messages correctly and generates suggested responses. When Applying Please provide: 1. Relevant projects 2. WhatsApp Business API experience 3. Slack or Telegram integration examples 4. Your preferred tech stack 5. Estimated hours to complete Version 1 6. Hourly rate or fixed-price estimate We are looking for a practical engineer who can deliver a simple and reliable solution rather than over-engineering the project.