KDA (Flink) to S3

A customer is building a streaming solution that processes messages from their customers. Data in the stream is sent from multiple customers - each JSON in the stream has a customerId that tells you what customer originally sent the data.

They want to store a copy of this data on S3, but partitioned by customerId. We could do this with multiple Firehoses (one for each customer). Is this possible to do with Flink - so use Flink to pull from the Kinesis stream and send to multiple destinations on S3, into files based on customer Id? I'm guessing this is possible - is it easy and can we use any existing libraries?

Thanks