Only the most trivial business systems can operate without any state.
If your application has any sort of shared, mutable state, you absolutely need to pick a region, or go really deep into the EC/consensus/clustering rabbit hole. With a dedicated region with 1 big DB, you can achieve latency figures (over the shared state) that would be infeasible with other schemes. Serializing transactions in a distributed manner is a circus compared to what Postgres has to do to achieve the same.
For better or worse, sticking a big SQL database in exactly one region will almost always be the best path for most forms of business. If latency/edge are still a concern at this point, that's when we maybe start talking about more specific geographies and standing up read replicas in those regions. In my experience, if you are peddling B2B webapps, no one will ever complain about east vs west coast latency unless you actually screwed something up in code.
Only the most trivial business systems can operate without any state.
If your application has any sort of shared, mutable state, you absolutely need to pick a region, or go really deep into the EC/consensus/clustering rabbit hole. With a dedicated region with 1 big DB, you can achieve latency figures (over the shared state) that would be infeasible with other schemes. Serializing transactions in a distributed manner is a circus compared to what Postgres has to do to achieve the same.
For better or worse, sticking a big SQL database in exactly one region will almost always be the best path for most forms of business. If latency/edge are still a concern at this point, that's when we maybe start talking about more specific geographies and standing up read replicas in those regions. In my experience, if you are peddling B2B webapps, no one will ever complain about east vs west coast latency unless you actually screwed something up in code.