Writing a custom DB driver comes for one reason only: you love a DB. That DB is part of your daily stack and you don't want to to start using another DB. That's OK. As any integration, we will start with the hooks.yml file. Let's see how we added rethinkdb into the db_drivers:

    metadata: '\Nuntius\Db\RethinkDB\RethinkDbMetadataHandler'
    operations: '\Nuntius\Db\RethinkDB\RethinkDbOperationHandler'
    query: '\Nuntius\Db\RethinkDB\RethinkDbQueryHandler'
    storage: '\Nuntius\Db\RethinkDB\RethinkDbStorageHandler'

The order of the items is not mandatory but could be much more easy to implement in that order.