Understanding Software Architecture  
Live Architecture

• Is in head(s) of software developer(s), the "software architecture"
• May be abstract or mostly concrete
• Is a "mental model", "wetware"; may be fuzzy, inaccurate, incomplete, incorrect …

Complexity

• Architecture simplifies the system, by concentrating on structure, not content or semantics
• Cognitive complexity: how hard to understand or visualize

Reverse Engineering

• Extraction of design (or architecture) from implementation and from developers
• "Design recovery"