As a UX lead I was challenged with making critical product decisions. Quickly I realized that the design intuition and taste which I was taught to trust wouldn't be enough. After leaving, I fully focused how to better inform design decisions and collaborate between design, data, and engineering.
Many professional fields use data analysis to inform strategic and practical choices. UX/UI Design has not yet fully embraced the power of data.
However the benefits are clear and materialise already with first data inquiries. The change is not overly complex, and is almost immediately applicable (provided data is already being collected by other departments).
The impact is also almost immediate. We estimated that 1/5 of our decisions are of higher quality. It became much easier to close leads. And my clients can measure return on investment in design work.