This report analyzes Claude Code’s complete feature set, architecture, and best practices for effective usage. Below are the five most actionable conclusions for developers.
1. Context management is the single most important operational skill. Claude’s 200K token context window fills rapidly — a fresh session starts with ~30K–45K tokens consumed by system prompts, tool definitions, CLAUDE.md, auto memory, and skill descriptions before any user input. Performance degrades noticeably around 147K tokens of actual usage [14]. The essential techniques are: use sub-agents for all research (they return summaries, not file contents), /clear
between unrelated tasks, /btw
for quick questions that never enter history, and /compact
with focus instructions when approaching the limit. A “kitchen sink” session where multiple unrelated tasks accumulate context degrades performance measurably.