Juniper Rentals keeps booking changes in an operational database, stores device readings in a lake table, and publishes a daily utilization warehouse. Each system can recover only as far as its retained evidence allows. These exercises use new workloads to combine capture boundaries, table snapshots, and safe backfills.
Look for the moment when a reader can see the result. Writing files, applying a change, and publishing a reconciled version are different events. You also need to distinguish source order from network order. A delayed update is still old when it arrives last. Some tasks ask for arithmetic; keep the units explicit so hours don't become days and file counts don't become row counts. The final choices test whether you can diagnose a plausible result that contains the wrong population.