For me it’s usually some context-specific, low-level DAG of functions/data flow. Maybe a higher level of C4 model depending on the scope of my work.

I’ve been studying this to build a VS code extension that visualizes my codebase as I work. Similar to Feynman’s point, there are many ways of visualizing the same task/section of code, but I’ve found some are more universally interpretable than others.