WhatsApp on Meta Cloud API

The problem

Verification outreach on WhatsApp ran through a reseller: one polled status, no control over templates, no inbox, no way to handle replies.

What I built

• Our own integration on the Meta WhatsApp Cloud API: send pipeline, webhook ingestion, BullMQ queues and template sync. About 41 merged PRs.
• An agent inbox, and a reply classifier with 12 intent handlers that routes replies on its own.
• Four outbound flows moved over behind feature flags, rolled out in stages from 1% to 100% with quality monitoring.
• Ops now edit, preview and A/B-test templates without a deploy, and opt-outs are enforced automatically.

Stack: Node.js, Meta Graph API, Webhooks, BullMQ, Redis, React.

What changed

11K+

messages to about 1,700 contacts in the first 10 weeks

~90%

of inbound replies routed with no agent (50 of 665 went to a person)

80% / 70%

outreach delivered / read

First

per-message delivery and read data the team ever had

Source: Messaging database and launch posts, first 10 weeks.

What went wrong, and the fix

• A 10% rollout stage had no fallback, so phone-only campaigns stalled. Fixed with a ramp to 50% and a reactivation script. Lesson: every rollout stage needs a way back.
• Template drift made one flow fail silently for 65+ hours. I replaced hardcoded template bodies with a live fetch and a 5-minute Redis cache.