If you have the opportunity, please do not build it like this. Referring to the architectural diagram, it is going to be much more efficient for the "Frontend" to persist the task data into a durable data store, like they show, but then the Frontend should simply directly call the "Store Consumer" with the task data in an RPC payload. There is no reason in the main execution path why the store consumers should ever need to read from the database, because almost all tasks can cut-through immediately and be retired. Reading from the database should only need to happen due to restarts and retries of tasks that fail to cut through.

Disclaimer/claim: I worked on this system and on gmail delivery.