Decide between ServiceTitan webhooks and polling for near-real-time job/invoice change notifications

Verified steps

1. Check the developer portal's webhooks documentation for current V1/V2 availability in your tenant before designing around webhooks, since ServiceTitan has been migrating webhook infrastructure and V1 has an announced deprecation date
2. If webhooks are available, register a callback URL and event subscriptions in "My Apps"; HMAC signing is optional but strongly recommended by ServiceTitan for V2 webhooks — if you enable it, verify the HMAC signature on every inbound payload before trusting it.
3. Implement idempotent handling of retried webhook deliveries — failed deliveries are retried at increasing intervals (roughly 10s, 30s, 60s, 300s) and can be manually replayed from the portal after that
4. If webhooks are not yet available for a resource, fall back to polling the relevant list endpoint with a modifiedOnOrAfter (or equivalent 'since' timestamp) filter on a fixed interval
5. Persist the last-seen timestamp/token between polling runs so you only process new or changed records each cycle
6. Re-check the developer portal's release notes periodically since webhook coverage has been expanding and endpoints you're polling today may get webhook support later