How to build monitoring dashboard that will monitor the status of AWS Health Dashboard, where we want to monitor the status of the Transcribe service in the Ohio region.

Just a note, AWS Health Aware also uses the Health API (and the related Business or Enterprise Support plan enabled on each account)

That is correct, I just mentioned it because it might serve as a good example. I've updated my answer to clarify.

You added an answer to your own question, if you want to follow up on a question I will probably be better to add a comment to my question :) (1) When you configure the rule you can select the service you are interested from a drop down list. You can follow the guide I linked, the provided example is for catching EC2 events, but it will work exactly the same for Transcribe. (2) After you have configured the rule, any AWS Health event posted for Amazon Transcribe that reaches your account invoke the target that you have configured in the rule. It looks like you want to write the output to S3, so you can do that by invoking your Lambda function when an event is received. The guide I linked also has an example of the payload.

Hi iddv, based on the suggestion (1) when I configure the even bridge rule, I can select the service I am interested in from a drop-down list. The service in my case is Transcribe - Done (2) After I have configured the rule, any AWS Health event posted for Amazon Transcribe that reaches my account invokes the target that I have configured in the rule - Done (3) I want to write the output to S3, so I can do that by invoking my Lambda function when an event is received - Done.

Lambda function looks like this:

import json
import boto3

def lambda_handler(event, context):
    s3 = boto3.client('s3')
    bucket_name = 's3bucket'
    key = 'aws-health-events/{}.json'.format(context.aws_request_id)
    
    event_data = json.loads(event['detail'])
    # Extract relevant information from the AWS Health event
    event_description = event_data['eventDescription'][0]['latestDescription']
    event_status_code = event_data['statusCode']
    event_start_time = event_data['startTime']
    event_end_time = event_data['endTime']
    
    # Upload the event information to S3
    s3.put_object(Body=event_description, Bucket=bucket_name, Key=key)
    
    return {
        'statusCode': 200,
        'body': json.dumps('AWS Health event successfully processed')
    }

Observations:

1. I can see some runtime metrics that lambda sends. But I'm unsure how to read it. Please refer the screenshot I've attached for your reference in the post above.
2. I Can't see any file in the S3 bucket

The metrics that you've posted seems to indicate that your function was invoked successfully once. There are a couple of things that you can do to debug this, such as (1) verify that you've deployed the latest version of your function, (2) make sure to test your function with a valid sample event, (3) add some debug logging to your code to verify that your code is doing what you expect it to do and (4) verify that your function has the correct permissions. Once you have it working with a sample event, you can log a request with AWS Support through the console to send a test event to your account, that will test your function end to end with a real AWS Health Event!