not head of engineering, but I hired for a Platform Engineering teams in the past. My take on this changes with how senior candidates I was looking at. When looking for someone with only couple of years of experience I would focus on their problem solving skills, if they are willing to learn, and eager to solve problems faster and better the next time. Typically there are some sparks of, we had a problem X that repeated itself, so I implemented a script/library/api/function to solve it. For candidates with more experience, especially staff engineers I looked for some experience already. This still doesn't have to be a platform team, but I want to either see them introduce a solution that helps their colleagues before, or they are already maintaining such tools. Often times these candidates have a mixture of soft and hard skills. Some people are more focused on building communities and leading others, while others focus more on technical part itself. Both skills are important to be successful. Especially as what I typically was after was engineering effectiveness, and for that I would expect more experienced candidates to go and do product discovery.