My general rule of thumb is "Use Postgres until you've discovered why you can't use Postgres."
Anything you introduce is another moving part you have to operate and maintain, and in the beginning, Postgres can probably handle it. Wait for load, see where its failing, and then you'll have a better idea if adding another tool is worth the cost.
Anything you introduce is another moving part you have to operate and maintain, and in the beginning, Postgres can probably handle it. Wait for load, see where its failing, and then you'll have a better idea if adding another tool is worth the cost.