The Timber service offers the following guarantees:
11-9s of durability.
Customer data is persisted and queried directly off of S3. In addition, Timber replicates all client data across regions protecting against the unlikely event of a catostrophic region failure. Timber data is also versioned protecting against accidental deletes for up to 3 days.
It's important to note that these are not archives or snapshots, this data is live queryable data resulting in significantly less (if any) downtime in the event of a failure.
Exactly once delivery.
Your data will be delivered and persisted exactly one time. Timber maintains a write ledger ensuring data does not get persisted multiple times in the event of failures or retries.