S3 Express One Zone is positioned as a serverless cache solution that excels in handling smaller objects, particularly those under 512KB, offering low latencies and a pay-per-use pricing model without significant upfront costs. Unlike traditional S3, which is optimized for large, long-lived objects, S3 Express One Zone eliminates IAM authentication on every request, uses session-based authentication for faster access, and confines operations to a single availability zone to reduce latency. The service is presumed to use SSDs, contributing to its swift performance, and it is ideal for objects with a lifecycle of at least an hour. However, the cost structure can become prohibitive for objects that frequently update or exceed 512KB. In scenarios requiring rapid updates or handling of spiky traffic, alternatives like ElastiCache Serverless or Momento Cache might be more suitable due to their distinct pricing and performance characteristics.