@huxlab: I met a friend who does R&D at Anthropic, with an annual salary of 1.5 million bucks. I asked her how she tuned Claude …

I met a friend who does R&D at Anthropic, with an annual salary of 1.5 million bucks. I asked her how she tuned Claude to its absolute peak. She straight-up tossed me a 30-minute internal screen recording that was originally not for public release. No exaggeration—this is hands-down one of the most valuable Claude hands-on resources across the entire web. Last night, I watched half of it, and chills ran down my spine: The way I've been writing prompts over the past two years was fundamentally wrong from the ground up. After finishing it, I distilled 5 core principles that Anthropic's internals are currently using: 1. Use XML to strictly isolate semantic blocks: If even you can't visually distinguish between data, business policies, and role boundaries with the naked eye, the model will only get more confused—strictly forbid mashing all rules into one massive blob of text. 2. Regularly clean out "defensive patches" from old models: New models have insanely strong compliance capabilities, and leftover historical negative constraints will lead to overfitting, stubbornly withholding correct info that's already in the context. 3. Instructions can't magically grant the model abilities out of thin air: Boldly emphasizing "must calculate accurately" in the Prompt is totally meaningless—complex computations must be decisively offloaded to Tool Calling for code execution. 4. Business trade-offs must be given for both ends of the full game balance: Just force-feeding one-sided operational costs will make the model extremely risk-averse; you have to simultaneously provide breach consequences and potential losses to activate the high-intelligence model's proper weighing. 5. Replace monolithic giant Prompts with a "generate-evaluate-fix" closed loop: Break down complex high-constraint tasks into a three-step lightweight pipeline—not only does it slash Token consumption and latency in half, but it dynamically accommodates runtime soft constraints. Strongly recommend bookmarking this right away—spend half an hour on it tonight, and your mindset will be completely reset.