Backend Events Missing Associated Frontend Events


#1

We use Snowplow in conjunction with our feature experimentation system, and we track experiments on the backend before the page is served to the user.

Therefore, when a user visits a page with an experiment, we should presumably receive both a backend experiment event and a frontend pageview event shortly thereafter.

However, we’re noticing that for a very significant number of backend experiment events, we are not receiving any frontend events associated with that backend event’s domain_userid.

We’re aware of a few reasons this could be happening: people leaving before the page loads, browsers blocking JavaScript, extensions blocking calls to Snowplow, etc.

However, we don’t think these alone can fully explain just how many single-event domain_userids we’re finding.

Are there any other possible explanations we might be missing?