This document summarizes a presentation on data-driven UI/UX design and A/B testing. It discusses how Obama raised $60 million through simple experiments on his website, testing different button text and media campaigns. The presentation outlines a 4-step process for A/B testing: 1) using data to identify problems, 2) forming hypotheses, 3) running experiments, and 4) evaluating results and deciding next steps. It emphasizes establishing key metrics and sample sizes to determine statistically significant results. Iteration is important - new hypotheses should be based on learnings. Regular testing allows continuous improvement even with small changes.