> Postgres is enough as long as you have a good multi-tenant setup e.g. a separate database per customer. Separate per customer has a lot of advantages (especi

> Postgres is enough as long as you have a good multi-tenant setup e.g. a separate database per customer. Separate per customer has a lot of advantages (especially around customer security and things like deletion) but you can also shard by customer right from the beginning; customer #1 in the "odd" shard, customer #2 in the "even" shard etc. Switching to database per customer if that is working well is relatively easy so you're future proofed both ways.