Earlier quoted context omitted.
If they understand their friend's work deeply, doesn't that imply they've done something comparable themselves?
No, let me give a specific example. Imagine you're interviewing a candidate and they're talking through how to design an analytics service. They begin talking about e.g. database architecture, and how this type of data is most appropriate for a star schema. They start talking about the tradeoffs of row versus column orientation. They mention they'll need to do indexing for performance and talk about the index space v…
Even though the whole thing could be very simple. Another thing is, they will come up with reasons that the issues with the user story/task for code/solution is due to environment or some other reasons like tools, framework, scalability and "bs".