The cloud-native orchestrator for the whole development lifecycle, with integrated lineage and observability.

dagster

Hello! I am trying to build a pipeline that triggers when a file on S3 is updated by checking it's `Last Modified` timestamp, following this example: <https://www.youtube.com/watch?v=PXN3zJJbjWg&amp;t=186s>. This example uses `@observable_source_asset`  to pull the timestamp and the subsequent assets get marked as `Stale` if the file is updated. It looks like I can use a Freshness Policy to run the stale assets, however, is there a way to have the `@observable_source_asset` check the timestamp without having to interact with it? Ideally, this process would work automatically.

Adding a `asset_reconciliation_sensor` doesn't seem to help.
```defs = Definitions(
    assets=[asset1, asset2, asset3, asset4],
    sensors=[
        build_asset_reconciliation_sensor(
            asset_selection=AssetSelection.assets(asset1, asset3, asset4),
            name="asset_reconciliation_sensor",
        ),
    ],
)```
Downstream assets still appear stale or overdue (if using freshness policy) when using this.