At Facebook, engineers have significant autonomy in developing new products, facilitated by tools that support rapid iteration in the Build->Measure->Learn->Build loop. Key tools include Gatekeeper, which allows controlled feature rollouts to test and validate functionality before a full launch; Quick Experiments (A/B), which replaces lengthy design debates with real-world user testing to quickly validate product ideas; and Deltoid, which maps the impact of new features on key metrics, aiding in debugging and ensuring features do not negatively affect overall product health. These tools highlight the importance of experimentation in product development and serve as the inspiration behind Statsig, a platform aiming to democratize sophisticated experimentation tools for developers, data scientists, and product managers. The narrative emphasizes the evolution of experimentation culture and infrastructure, drawing lessons from Facebook's experience and advocating for broader access to these methodologies.