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Custom Audiences

Custom audiences let you target specific groups of users beyond the regular targeting options. Custom audiences can be configured for any experiment through the experimenter UI:

custom audience screenshot

They are:

  • Optional - Don't use them unless you need to limit the experiment to specific group of users.
  • Specific to a particular application (Not all audiences can target all applications)
  • Evaluated on clients via an expression language (JEXL)

Right now, Desktop-only audiences will appear as options for mobile experiments. This is a known issue

How to add a new custom audience#

Create a PR against constants/ (see this example. You will need to set up a local dev environment (make sure you cp .env.sample .env) and run make makemigrations && make check to generate a migration and run tests.

Request review from a console core team member. It should be available in the Experimenter UI a few minutes after the PR has merged.

⚠️ New custom audiences should be tested by the core Nimbus team before they are used in production. This could involve any or all of the following:

  • Test the whole JEXL expression on each application/device it is intended to run on.
  • Ask QA to help verify it by creating a dummy experiment.
  • Launch an A/A in nightly to see if real users enroll with the correct