To set up a system to monitor website metrics in real-time in AWS, you can use a combination of services such as Amazon CloudWatch, AWS Lambda, and Amazon SNS. Here are the high-level steps:

• Set up Amazon CloudWatch: First, you need to enable CloudWatch Metrics for your website. This can be done by installing the CloudWatch agent on your web server, which will collect metrics such as CPU utilization, memory usage, and network traffic.
• Create a CloudWatch Alarm: Next, you can create a CloudWatch Alarm to monitor a specific metric, such as HTTP response time or server errors. When the threshold for the metric is breached, the alarm will trigger an action.
• Configure AWS Lambda: You can create a Lambda function that will execute a specific action when the CloudWatch Alarm is triggered. For example, the function could send an email notification or post a message to a Slack channel.
• Set up Amazon SNS: You can create an SNS topic that will receive notifications from the Lambda function. SNS can then deliver the notifications to subscribers via email, SMS, or other channels.
• Test and Monitor: Finally, you can test the system by generating traffic to your website and monitoring the metrics in real time. If the threshold is breached, the CloudWatch Alarm will trigger the Lambda function, which will send notifications to the SNS topic.

By setting up this system, you can monitor website metrics in real time and take action to resolve issues as they occur. This can help you ensure that your website is always performing optimally and provide a better user experience to your customers.