Which file format is used for the segment metadata file stored in Amazon S3?

• A. XML
• B. JSON
• C. CSV
• D. YAML

Answer: (B)

JSON is used because it provides a lightweight, text-based way to represent structured metadata with nesting and arrays. Segment metadata often includes multiple fields (such as segment name, description, rules or criteria, creation and modification timestamps, and lists of attributes or conditions). JSON can naturally model all of these in a hierarchical way, which is easy to read by humans and straightforward to parse by software in data pipelines and AWS tooling. It’s also widely supported across languages and services you’ll use with S3, making ingestion, validation, and processing in ETL or analytics workflows seamless.

XML tends to be more verbose and heavier to parse, which isn’t ideal for metadata that needs to be processed quickly at scale. CSV is flat and cannot represent nested structures needed for complex segment definitions. YAML is human-friendly but isn’t as universally adopted in automated data workflows and can introduce parsing quirks in pipelines. JSON hits the sweet spot for representing comprehensive, machine-readable metadata stored in S3.