How it works
Database CDC reads the transaction log, such as the Postgres write-ahead log, and publishes each row change in order. For SaaS platforms without log access, CDC is built from change feeds, webhooks, modified-since queries or periodic comparisons of snapshots. Deletes are the hard part: many APIs simply stop returning a deleted record, which only a comparison can detect.
Example
A ledger API has no deleted-records endpoint. A nightly comparison finds that invoice INV-2207 disappeared, and emits a delete event so downstream systems remove it too.
In integrations
Unify Sync is designed to combine native webhooks, modified-since polling and snapshot comparison per platform, so changes on the Unify Graph, deletes included, arrive as one consistent stream of events and webhooks. Reliable change capture is what keeps a stored copy trustworthy. Without delete detection and ordering guarantees, small errors accumulate until the copy no longer matches the source.