Yes, but if you do need to, it's much simpler if you were using UUID since the beginning. I'm personally not convinced that any of the tradeoffs that comes with a more traditional key are worth the headache that could come in a scenario where you do need to shard. I started a company last year, and the DB has grown wildly beyond our expectations. I did not expect this, and it continues to grow (good problem to have). It happens!