Exam AWS Certified Solutions Architect - Associate SAA-C03 topic 1 question 833 discussion

A - Requires a separate Lambda function to preprocess and publish transformed data to multiple queues. Unnecessary. B - SNS filtering operates at the subscription level, not the event transformation level, making it harder to customize data subsets for specific Lambda functions. C - Amazon EventBridge: event-driven systems. Input Transformer: ensures each receives only the required subset of data. D - Synchronous invocation adds tighter coupling between Lambda functions and the validation steps.

SNS and Message Filtering - With SNS, message filtering allows you to control which subscribers receive messages based on attributes. However, the entire message is sent to each subscribed Lambda function; only those that match the filter criteria are processed. EventBridge and Input Transformation - EventBridge enables you to define rules that transform or modify events before they reach their targets. This allows you to customize the event payload, ensuring each validation step receives only the relevant information. "The company wants to ensure that each validation step Lambda function has access to only the information from the order event that the function requires." Therefore, C is the answer.

Event-driven Architecture + Each validation step needs ONLY a subset of the order EVENT created. Best way to transform this order even is EB Transformer.

Answer C I wasn't sure but looks like EB with Input Transformation will allow for sending data which were choosed per destination https://docs.aws.amazon.com/eventbridge/latest/userguide/eb-pipes-input-transformation.html

not B because SNS cannot make messages manipulation, the option "message body filtering" will make discard or forward the FULL message if there is a matching field: https://docs.aws.amazon.com/sns/latest/dg/sns-message-filtering.html C - eventbus instead can manipulate event: https://docs.aws.amazon.com/eventbridge/latest/userguide/eb-event-bus.html D - Works, but too much operation IMO

Why can't it be B?

It is D. It is one order event, not "events from many sources" The main lambda parse the info to pieces, then makes synchronous invocations of the validation step Lambda functions on separate threads, and wait them to complete.

IMO, C "An event bus is a router that receives events and delivers them to zero or more destinations, or targets. Event buses are well-suited for routing events from many sources to many targets, with optional transformation of events prior to delivery to a target."

Option C

https://docs.aws.amazon.com/eventbridge/latest/userguide/eb-event-bus.html