Design Individual and Bulk Merchant Product Updates with Image Uploads

Design a merchant-facing system that supports updating product attributes individually or in bulk and uploading product images. Explain the APIs, storage, processing flow, and how merchants learn which changes succeeded. ### Constraints Product count, batch size, image size, update rate, and consistency targets are not specified. State any design assumptions. Preserve both single-item and bulk updates, and treat image upload as a distinct data path that must be coordinated with product metadata. ### Clarifying Questions - Are attribute updates partial patches or complete replacements? - Must a bulk request succeed atomically, or may individual items fail independently? - When should an uploaded image become visible, and are validation or transformations required? - Can multiple clients update the same product concurrently? ```hint Track the unit of success A successful upload of bytes does not necessarily mean that the product now references a valid, processed image. ``` ### What a Strong Answer Covers - Merchant authorization, product identity, attribute validation, and concurrency control. - A bounded single-update path and durable bulk-job processing with item-level results. - Image storage, validation, lifecycle management, and observable failure handling. ### Follow-up Questions - How would a merchant retry a partially failed batch without repeating successful work? - What happens if metadata persistence fails after an image has been uploaded?