title: Advise on cross account s3 and lambda integration
body: <p>There are two accounts:</p>
  <p>Account-A (our team does not own this service) -&gt; s3 Bucket (exampleBucket) is located.</p>
  <p>Account-B (our team owns) -&gt; Lambda function (myLambda)</p>
  <p>We need to execute a Lambda function (myLambda) whenever a new object is created in the s3 bucket (exampleBucket).</p>
  <p>I have found at-least 2 ways to do this:</p>
  <p>S3 (Event Notification) -&gt; Lambda</p>
  <p>S3 (Event Notification) -&gt; SNS Topic -&gt; Lambda reads the notification from SNS</p>
  <p>S3 (Event Notification) -&gt; SQS Topic -&gt; Lambda reads the notification from SQS</p>
  <p>Additional Info:</p>
  <ol>
  <li><p>Both Lambda and S3 are in the same region (different AWS accounts)</p>
  </li>
  <li><p>Assume we have all the necessary permissions</p>
  </li>
  <li><p>We get a new object in the bucket once every (~5 seconds)</p>
  </li>
  <li><p>There are enough Lambdas (concurrent executions) to handle all the invocations.</p>
  </li>
  </ol>
  <p>I need how to determine which would be better, in terms of:</p>
  <ol>
  <li><p>Latency (Time of creation of object in S3 - Executing Lambda function)</p>
  </li>
  <li><p>Maintenance</p>
  </li>
  <li><p>Monitoring</p>
  </li>
  <li><p>Scaling (I am assuming since all the services are managed by AWS, this shouldn't be an issue)</p>
  </li>
  </ol>