GrowthBook

GrowthBook is an open-source feature flagging and experimentation platform offering both self-hosted and cloud options. The platform combines feature flags with A/B testing, supports warehouse-native analytics with Snowflake, BigQuery, Postgres, and ClickHouse, and provides Bayesian and frequentist statistical engines. GrowthBook includes SDKs for major languages and frameworks, visual editor for no-code experiments, and integrations with Mixpanel, Amplitude, and Segment. The open-source nature makes it popular with engineering-led teams, startups, and enterprises with strict data residency requirements who want feature flagging and experimentation without vendor lock-in.