I think being able to be productive without having the whole thing in your head is one of the important skills of working at BigCo. It's definitely more awkward

I think being able to be productive without having the whole thing in your head is one of the important skills of working at BigCo. It's definitely more awkward and I'm sure leads to an increased number of bugs, but it lets shifting teams and priorities move forward. Some people struggle a lot with this though, especially if they've only ever worked on their own programs or programs designed in a small and tight group (e.g school projects). It's definitely a skill. After an intern experience I changed up one of my phone screen sections -- we have to do a phone screen (I modeled my favorite variation on Yegge's), I try to change it up from time to time though to make it somewhat interesting for both people, test different ideas of what questions produce what signals and what signals are valuable, and at least never make it a whiteboard or accurately-code-well-known-freshmen-problems-like-sorting-algos hazing. I used to reserve a section for discussing program design in a hypothetical board game program, I took that out to instead give the person a description of a simple web app with an accompanying ~100 LoC describing the architecture and component hooks (simplified and mocked a bit from our actual code, it has a startup that creates top level components like the PageBody component and the Header component, the Header component creates a Navigation component and whatever else, the Navigation component creates navigation elements...) and a problem statement that involves threading some new Component data from the root to a leaf using the existing framework in order to make a proposed code change work. So it's not that hard objectively, it's mainly adding a new function param in a couple component initializing functions and updating call sites, but it requires being able to read a chunk of code, ignoring most of it, but understanding just enough of it in context to make the change. The new intern who got through this (took ~20-25 mins) ended up being pretty solid, and I think the test would have negatively differentiated the prior intern with other candidates we had thought of as about equivalent...