Optimizely limits integrations by plan.
The Optimizely X Essential & Business options have integrations with Google Analytics, Google Adwords, Clicktale and Adobe Analytics. The Enterprise variant supports integrations with solutions like BlueKai, Lotame, Demandbase and Lytics.
There are several integrations that are maintained by Optimizely technology partners. But these are limited to some 20 tools.
An integration with Shopify or Salesforce does not feature on the Optimizely site or in Optiverse (their learning hub).