Uncertainty lies in ourselves: in our ability to understand the software system, understand and use abstractions, process input data, adhere to project rules, communicate and apply methodologies… It’s all about how people think. The cognitive entropy refers to doubts in the understanding of the software system that is being developed. Our goal is to constantly reduce this entropy by making decisions based on data and evidence, and by acknowledging the limits of our cognitive processes. A way to understand the extent of uncertainty is by applying cognitive pressure to parts of the system.