Systematic approach to understanding unfamiliar code - orienting in a new codebase, tracing behavior, building a mental model before changing anything, and analyzing third-party libraries or inherited projects. Use when joining/inheriting a project, before modifying code not written in this session, when asked "how does this work" or "analyze this repo/library", when evaluating code found online, or as the research phase before any feature in an existing system. Trigger before proposing changes to any codebase not already mapped in context.
