An e-commerce alert is not complete when an API accepts a message. It is complete when the application records a terminal delivery state, suppresses an invalid recipient, or escalates through a separately governed channel. Short answer: use a dedicated SMS API for a small critical-alert worker when template ownership and direct status control matter; keep AWS SNS when SMS belongs inside an existing cloud messaging stack, and prefer a callback-capable provider when escalation must begin in under a minute.
That choice creates work. A direct API keeps the send path narrow, but polling, retries, dead-letter handling, and country-specific fallback rules remain application responsibilities. For critical alerts, those responsibilities need the same idempotency and audit discipline as a ledger entry: one intent, one durable identifier, and an append-only record of every state observation.
No provider turns carrier delivery into exactly-once delivery.
Implement the template control plane in Node.js
Start with the contract, not the vendor. The application owns an immutable alert intent containing the business event ID, recipient, template version, jurisdiction, and escalation deadline. Template ownership is the decision axis: if compliance reviewers must approve and reproduce the exact text that was sent, keep the canonical template version in the application and treat a provider template ID as deployment metadata. If a provider must own localization or regulatory registration, record that provider template ID beside the application version rather than letting it become invisible configuration.
