An ecommerce company runs a multi-tier application on AWS.

Caching frequently accessed, identical datasets is a well-established way to improve backend application performance by reducing load on the database. Amazon ElastiCache with Redis (open source) offers a fast, in-memory data store to cache query results, reducing latency and database requests.

Option B directly addresses the problem by offloading repeated read requests from the database to the cache.

Option A (SNS) is a messaging service and is unrelated to caching or improving database performance. Option C (DAX) accelerates DynamoDB but the backend uses RDS MySQL, so DAX is inapplicable. Option D (Data Firehose) is a data streaming service and does not optimize database read performance.