This workshop is meticulously designed to explore the nuances of experimental design used in various fields. Attendees will be introduced to real-world use cases and applications, illustrating the power of well-structured experiments. The workshop emphasizes the essence of different types of experimental designs, with special emphasis on the widely applied A/B testing methodology. It will unravel the technicalities of the significance level and power concepts, key pillars in making informed decisions based on experimental results. We dive deeper into the intriguing aspect of sample size calculation, an essential factor in achieving robust experiment results. Our journey culminates in a comprehensive walk-through of designing an experiment and effectively evaluating its outcomes.