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projects_system_design.html

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-  This diagram describes a general design for a backfill subsystem to replace a legacy service where transformations are live computed on each request. The new system leverages the legacy system's transformations library and stores the transformed data for quick retrieval. This poses a few challenges as data needs to be backfilled regularly as low frequency data is ingested and when there are code changes impacting transformations.
+  This diagram describes a general design for a backfill system of a feature service that consumes data at two frequencies. Lower frequency data is less accurate but highly available and consistent. Higher frequency data has frequent outages and anomalies. Therefore the data needs to be backfilled regularly as low frequency data is ingested. Targeted backfills are also executed and when there are code changes impacting transformations.
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