GrowthBook is the most popular open source experimentation and feature flagging platform. Created in 2021 , GrowthBook is a modern and highly customizable platform that works with your unique needs and data structures. Get all the power of a custom in-house platform without having to build it yourself. GrowthBook features high performance SDKs in most popular languages for feature flags, and is architected to not be in the critical rendering path. Our A/B testing platform uses your existing data warehouse, and can be completely customized to your data needs. We support most popular event tracking tools, as well as custom support for most data warehouses- we even support Mixpanel and Google Analytics. No black-box! Get complete transparency into your data, view queries, and even export to Jupyter notebooks.