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Experiments can be conducted by any GitLab team, most often the teams from the [Growth Sub-department](https://about.gitlab.com/handbook/engineering/development/growth/). Experiments are not tied to releases because they primarily target GitLab.com.
Experiments are run as an A/B/n test, and are behind an [experiment feature flag](../feature_flags/#experiment-type) to turn the test on or off. Based on the data the experiment generates, the team decides if the experiment had a positive impact and should be made the new default, or rolled back.
Each experiment should have an [experiment rollout](https://gitlab.com/groups/gitlab-org/-/boards/1352542) issue to track the experiment from rollout through to cleanup and removal.
The rollout issue is similar to a feature flag rollout issue, and is also used to track the status of an experiment.
Experiments must have corresponding [frontend or feature tests](../testing_guide/index.md) to ensure they
exist in the application. These tests should help prevent the experiment code from
being removed before the [experiment cleanup process](https://about.gitlab.com/handbook/engineering/development/growth/experimentation/#experiment-cleanup-issue) starts.
[`GLEX`](https://gitlab.com/gitlab-org/ruby/gems/gitlab-experiment) - or `Gitlab::Experiment`, the `gitlab-experiment` gem - is the preferred option for implementing an experiment in GitLab.
Therefore, you should postpone this effort until the [experiment cleanup process](https://about.gitlab.com/handbook/engineering/development/growth/experimentation/#experiment-cleanup-issue).
1. Review the Pajamas guidelines for [icons](https://design.gitlab.com/product-foundations/iconography/) and [illustrations](https://design.gitlab.com/product-foundations/illustration/).
When there is a case on GitLab.com (SaaS) that necessitates turning off all experiments, we have this control.
You can toggle experiments on SaaS on and off using the `gitlab_experiment` [feature flag](../feature_flags).
This can be done via chatops:
- [disable](../feature_flags/controls.md#disabling-feature-flags): `/chatops run feature set gitlab_experiment false`
- [enable](../feature_flags/controls.md#process): `/chatops run feature delete gitlab_experiment`
- This allows the `default_enabled` [value of true in the yml](https://gitlab.com/gitlab-org/gitlab/-/blob/016430f6751b0c34abb24f74608c80a1a8268f20/config/feature_flags/ops/gitlab_experiment.yml#L8) to be honored.