# prompt-engineering

OpenAI's GPT-5.5 prompting guide: describe the outcome, not the process. ALWAYS/NEVER lists out; personality vs. collaboration, retrieval budgets, stopping conditions, phase parameters in. Cursor's GPT-5 case study included. Anthropic Opus 4.7 went the same direction in SP-175.

Anthropic just published a postmortem confirming Claude Code really did feel dumber this past month — not one bug, but three independent changes rolling out on different schedules that stacked into what looked like a broad regression. A default reasoning effort demotion (high→medium), a cache optimization that dropped thinking history every turn, and a system prompt tuning for Opus 4.7 verbosity that cost 3% on evals. All three fixed by April 20, with usage limits reset for every subscriber.

SP-175 covered Opus 4.7 hard specs. This is the workflow layer. Pawel Huryn argues intent is the new unlock. Two-layer CLAUDE.md, per-call effort toggle, batch questions, show-don't-forbid, kill stale scaffolding, review plans not diffs — plus Anthropic/OpenAI converging.

Anthropic released two Opus 4.7 best practices — a Claude Code guide and a full prompting docs page. 4.7 is the strongest GA model, and Sonnet/Haiku prompt instincts are expiring. One cheat sheet: three must-knows, effort ladder, 4.6→4.7 diffs, copy-paste snippets.

Prompt caching should save you 90% on token costs — but one obscure bug can silently make you pay 10x more. From DANGEROUS_uncachedSystemPromptSection to the cch=00000 billing trap hidden in Claude Code's DRM, here's why prompt engineers now need to be accountants too.

Ole Lehmann shares a method that applies Karpathy's 'autoresearch' concept to Claude skills — letting an agent test, tweak, and improve your prompts automatically. His landing page copy skill went from 56% to 92% pass rate with almost zero manual work.

Thariq from Anthropic shares what they've learned from running hundreds of Claude Code Skills internally: Skills are folders not just markdown files, they cluster into 9 categories, and the secret sauce is in the gotchas section, progressive disclosure, and writing descriptions for the model — not for humans.

Someone took the Claude Certified Architect exam content and broke it all down — five domains, core concepts, anti-patterns, and hands-on suggestions. The certificate doesn't matter; the knowledge does.

Vishwas shares a complete guide to CLAUDE.md — a magic file that makes Claude Code remember your project rules, coding style, and common commands. No more repeating yourself every session.

klöss's UI/UX Auditor prompt: turns AI into an auditor with Steve Jobs and Jony Ive's design philosophy, checking every pixel on every screen

klöss's complete XML prompt framework: 6 core tags + 11 advanced tags, never copy-paste prompts again