If you are using the Optimizely X Web Product, you’ll notice that while many features are the same, there are a number of differences between using the Full Stack product and the Web product.
For SDK projects in Full Stack, you specify a primary language for developing experiments. This is the language of the application or service you're experimenting in.
SDK projects in Full Stack don’t include the Visual Editor. SDK projects are designed to allow you to run experiments in any application or service you're developing. Use them to create experiments as flags in the application code and launch them with the regular code deploy process instead of creating experiments with a Visual Editor.
SDK projects include some additional features that aren’t currently available for Web projects, including webhooks, whitelisting, mutually exclusive experiments and datafile versioning.