Explaining design decisions requires the ability to discern the difference between the objective and subjective. Engineering is objective - the thing works and plays or it doesn’t. A bridge can mathematically sustain a load of 20,000 pounds or it can’t. Design is subjective - why is the background blue? The CEO likes blue? You have to be able to explain why the blue is blue.
I once worked on a team project where our efforts were diverted to support a last minute product launch. 24 hour burndown and deliverables checked in on the hour. In the morning the general manager wanted all the buttons turned into H1 size text. No heirarchy, no consideration for usability.
The key is to use facts and data to make the subjective more objective.
We presented user research that showed that users are confused by a field of identical choices, which is what a page full of buttons the same size would be. By showing the manager data on user behavior and preference, we were able to turn a subjective decision based on feelings into an objective decision based on facts.
The ability to turn the conversation from subjective to objective begins with establishing trust and credibility.
Does your team consistently deliver quality solutions on time? Do you regularly present research findings to your executives and the rest of your team? I have the best success when I proactively establish a good relationship with engineers, PMs, business owners, and executives.