A homegrown POST plus a retry queue looks fine for one internal consumer. Cost shows up later: dual-signature rotation, idempotent ingest, SSRF-safe egress, customer-visible attempt logs, replay versus retry, and support load when a tenant's receiver is down. DIY has no vendor invoice; it still has cloud, engineering, incident and support cost.
Managed Standard Webhooks-style signing, exponential backoff with jitter, a customer portal, Test/Live keys, and a dashboard for failed destinations. Outemit does not replace your product API. You still emit events; we attempt delivery.
Both approaches send HTTPS requests to customer servers. Neither is an inbound API gateway. Stay on DIY if you have a single destination, no tenant self-service, and an on-call team that already owns this. Use a vendor when customer-facing webhooks are a product surface.