The problem with this route is that as you scale everything breaks. You end up putting the events or activities table on DynamoDB or you have to store user pres

The problem with this route is that as you scale everything breaks. You end up putting the events or activities table on DynamoDB or you have to store user presence in Redis or you have to vertically or horizontally shard and have to move all that business logic that was in your DB back into the application layer anyway. Also, it's just harder to debug stored procedures when they do the wrong thing than it is with a typical problem in application code on a stack like Rails or Django.