Which next step is MOST likely to improve the data ingestion rate into Amazon S3?

Explanations:

Increasing the number of S3 prefixes for the delivery stream will not directly improve the ingestion rate into S3. While it can enhance performance by distributing load, the fundamental bottleneck is likely in the data stream ingestion, not S3 itself.

Decreasing the retention period for the data stream does not improve the ingestion rate into S3. It only reduces the amount of time that data is retained in the stream before it is discarded, which does not address the backlog or ingestion performance.

Increasing the number of shards for the data stream allows for higher parallelism in data ingestion. Each shard has a maximum ingest rate, and by increasing the number of shards, the overall throughput of the data stream can be improved, allowing more data to be processed and ingested into S3 faster.

Adding more consumers using the Kinesis Client Library (KCL) will not directly resolve the issue of data ingestion rate into S3. If the bottleneck lies with Kinesis Data Streams and Firehose, merely adding more consumers will not address the ingestion limitations imposed by the current configuration of shards.