I have a conversation about application architecture, coding issue candidates have faced in the past and how they resolved those issues. I look at their GitHub profiles and I check letters of recommendation. For some positions we give a take home mini-project that is clearly not related to our current projects.

Senior people can usually tell you the mistakes they made as a junior dev and what they learned from those mistakes. They understand the nuanced differences between code ownership and accountability.

Frankly I could care less if a candidate can balance a tree, that is what the standard library is for or google or chatgpt. On the other hand, I am interested in knowing if a senior client understands why you might want to balance a tree or knowing when to force a full table scan rather than use an index.