An Anthropic engineer has shared insights on how to optimize token usage in Claude Code by leveraging caching mechanisms, potentially saving users up to 300 million tokens weekly. The key to reducing costs lies in reusing previously processed context, with cached tokens costing only 10% of regular input tokens. By maintaining consistent session prefixes, users can effectively utilize cache layers, including system prompts, tool definitions, and conversation history, to minimize redundant computations. To maximize cache efficiency, users are advised to avoid leaving sessions idle for over an hour, perform proper session handoffs when switching tasks, and place large documents into Projects rather than pasting them into conversations. These practices help maintain a high cache hit rate, which not only extends session durability but also reduces service costs for Anthropic. The engineer emphasizes treating context as asset management to enable continuous cache reuse and enhance the longevity of coding sessions.