Solved Remote Event Receiver on updated will be firing multiple times in SharePoint 2013/16

 Most of you who are working on Remote Event Receivers must have encountered this issue of "Updated event getting fired multiple times". The following code should fix the issue:

Use the adding or updating events. And then update the title within the "ProcessEvent" as follows:

public SPRemoteEventResult ProcessEvent(SPRemoteEventProperties properties)
    {
        SPRemoteEventResult result = new SPRemoteEventResult();

            result.ChangedItemProperties.Add("Title", "NEW Title");
            result.Status = SPRemoteEventServiceStatus.Continue;
        return result;
    }

or

   public SPRemoteEventResult ProcessEvent(SPRemoteEventProperties properties)
        {
            SPRemoteEventResult result = new SPRemoteEventResult();
            if (properties.EventType == SPRemoteEventType.ItemAdding ||
                properties.EventType == SPRemoteEventType.ItemUpdating)
            {
                // Generate Image Search for Flower
                result.ChangedItemProperties.Add("Title", 
                    "My New Title");
                result.Status = SPRemoteEventServiceStatus.Continue;
            }
            return result;

        }


Reference:

http://code.msdn.microsoft.com/office/SharePoint-2013-Add-list-2c6e71e0