For microservices and modern web applications, the cache is not the only tool that exempts the database. It is a matter of strategy. Something that can be widely used to make the application much more performative than it would be without caches. But choosing well and setting the cache layer are crucial to success.
There are cache strategies consisting of using the cache as a loading point for the database. Observe the following diagram:
In the preceding diagram, we see that the requests arrive for our API, but are not directly processed and sent to the database. All valid requests are cached and simultaneously put in a row.
Consumers read the queue and process the information. Only after processing the information is the data stored in the database. Eventually, it is rewritten in the cache for data updates that are being consolidated in the database. With this strategy, any information requested by the API will be placed directly in the cache before it passes through the database...