{
  "context": "This evaluation assesses how effectively the engineer uses AWS Lambda Powertools' Streaming module to process large S3 files efficiently. The focus is on proper usage of S3Stream for seekable access, transformation chaining with GzipTransform and CsvTransform, and leveraging lazy loading to handle files larger than Lambda memory.",
  "type": "weighted_checklist",
  "checklist": [
    {
      "name": "S3Stream initialization",
      "description": "Uses S3Stream (from aws_lambda_powertools.utilities.streaming) to create a seekable stream from S3 bucket and key, enabling random access to file contents.",
      "max_score": 25
    },
    {
      "name": "GzipTransform usage",
      "description": "Applies GzipTransform to decompress gzipped files on-the-fly when the S3 object key indicates gzip compression (e.g., .gz extension), avoiding memory-intensive full file decompression.",
      "max_score": 20
    },
    {
      "name": "CsvTransform usage",
      "description": "Uses CsvTransform to parse CSV data as a stream, providing DictReader-like functionality that returns rows as dictionaries with column headers as keys.",
      "max_score": 25
    },
    {
      "name": "Transformation chaining",
      "description": "Correctly chains transformations in the proper order (GzipTransform -> CsvTransform) to decompress and parse CSV data in a single streaming pipeline, demonstrating understanding of the transformation composition pattern.",
      "max_score": 20
    },
    {
      "name": "Stream operations",
      "description": "Uses appropriate stream methods for reading data (e.g., reading specific rows, iterating through CSV records) and leverages the IO[bytes] interface for efficient data access without loading the entire file.",
      "max_score": 10
    }
  ]
}