Consumer1.cs

string queueUrl = "YOUR_QUEUE_URL";
using (var client = new Amazon.SQS.AmazonSQSClient(Amazon.RegionEndpoint.APSoutheast2))
{
    while (true)
    {
        // Get the messages
        var response = client.ReceiveMessage(queueUrl);

        // Check our response
        if (response.Messages.Count > 0)
        {
            for (int i = 0; i < response.Messages.Count; i++)
            {
                // Send an email
                Console.WriteLine("Sending email");

                // Delete our message so that it doesn't get handled again
                var receiptHandle = response.Messages[i].ReceiptHandle;
                client.DeleteMessage(queueUrl, receiptHandle);
            }
        }
    }
}

Consumer2.cs

string queueUrl = "YOUR_QUEUE_URL";
using (var client = new Amazon.SQS.AmazonSQSClient(Amazon.RegionEndpoint.APSoutheast2))
{
    while (true)
    {
        // Get the messages
        var response = client.ReceiveMessage(queueUrl);

        // Check our response
        if (response.Messages.Count > 0)
        {
            for (int i = 0; i < response.Messages.Count; i++)
            {
                // Send an email
                Console.WriteLine("Sending SMS");

                // Delete our message so that it doesn't get handled again
                var receiptHandle = response.Messages[i].ReceiptHandle;
                client.DeleteMessage(queueUrl, receiptHandle);
            }
        }
    }
}

Consumer3.cs

string queueUrl = "YOUR_QUEUE_URL";
using (var client = new Amazon.SQS.AmazonSQSClient(Amazon.RegionEndpoint.APSoutheast2))
{
    while (true)
    {
        // Get the messages
        var response = client.ReceiveMessage(queueUrl);

        // Check our response
        if (response.Messages.Count > 0)
        {
            for (int i = 0; i < response.Messages.Count; i++)
            {
                // Send an email
                Console.WriteLine("Updating Cache");

                // Delete our message so that it doesn't get handled again
                var receiptHandle = response.Messages[i].ReceiptHandle;
                client.DeleteMessage(queueUrl, receiptHandle);
            }
        }
    }
}

Producer.cs

string INCIDENT_CREATED_ARN = "arn:aws:sns:ap-southeast-2:835265634988:INCIDENT_CREATED";
string INCIDENT_UPDATED_ARN = "arn:aws:sns:ap-southeast-2:835265634988:INCIDENT_UPDATED";

using (var client = new Amazon.SimpleNotificationService.AmazonSimpleNotificationServiceClient(Amazon.RegionEndpoint.APSoutheast2))
{
    while (true)
    {
        Console.WriteLine("Press 1 to create a new incident, or 2 to update an existing incident.");
        var key = Console.ReadKey();

        if (key.KeyChar == '1')
        {
            Console.WriteLine("Creating incident.");
            client.Publish(INCIDENT_CREATED_ARN, "Incident created.");
        }
        else if (key.KeyChar == '2')
        {
            Console.WriteLine("Updating incident");
            client.Publish(INCIDENT_UPDATED_ARN, "Incident updated.");
        }
        else
        {
            Console.WriteLine("Unrecognised action.");
        }
    }
}