The event producer in this case is one of our Snowplow trackers (https://github.com/snowplow/snowplow-javascript-tracker) - and these tracking SDKs do indeed attach a UUID as a unique event ID at event creation time.

However, this event ID is not enough to identify and then dedupe all types of duplicate events. This blog post provides more information:

https://snowplowanalytics.com/blog/2015/08/19/dealing-with-d...

Big thanks to pragmacoders for putting this tutorial together! It's awesome seeing what you are doing with the Snowplow platform :-)