An interactive tool demonstrates derivative-free optimization by tuning espresso shot parameters (grind, dose, temperature, time) to achieve optimal extraction (~20%) and brew ratio (~1:2). Trust-region methods like PRIMA_BOBYQA find good recipes within ~12 pulls while random search struggles, illustrating why sample-efficient optimization matters for expensive black-box tuning problems.
Roastbook is a self-hosted coffee journal app that tracks espresso shots, beans, and brewing data with optional AI assistance for label scanning, roaster research, and brew recommendations. Users retain full control over their data stored on personal infrastructure, with AI features requiring an OpenAI API key and offering detailed brewing analytics and mobile-first design.