MLS-C01 Data Engineering Practice Question

Correct answer & explanation

Increasing the number of shards to 10 ensures that the Kinesis stream can support up to 10 concurrent Lambda invocations (one per shard). With a batch size of 100, each invocation processes 100 records, resulting in 100 invocations per second (10,000 records / 100 per batch). At 200 ms per invocation, the required concurrency is 100 * 0.2 = 20, well within the default 1,000 concurrency limit. Option A is incorrect because reducing the batch size to 10 would increase invocations to 1,000 per second, requiring 200 concurrent executions, which still fits but is less efficient; the main issue is that reducing batch size does not reduce throttling risk as it increases invocation rate. Option B is incorrect because Kinesis Data Firehose does not natively support Lambda for per-record transformations before writing to DynamoDB; it primarily targets S3, Redshift, or Elasticsearch. Option C is incorrect because increasing Lambda memory typically reduces execution time but does not lower concurrency requirements; moreover, 3,000 MB may not reduce time below 100 ms enough to avoid throttling at high throughput.