Claude Code skill packs: 10 skills that cut my development time in half

I've been using Claude Code daily for 6 months. These 10 skill packs changed how I work — and cut my development time roughly in half. Before I get into the list: Claude Code skills are reusable instruction sets you drop into your project that tell Claude how to approach specific tasks. They're not plugins or extensions — they're structured prompts that encode expert-level workflows. Think of them as hiring a specialist for each part of your stack, permanently. Here's what actually moved the needle. 1. TDD skill — forces test-first on every feature Without this, I kept writing code first and "maybe tests later" (spoiler: never). The TDD skill enforces the red-green-refactor loop at the prompt level: Claude won't write implementation code until it's written a failing test. Before: Write feature → realize testing it is annoying → ship without tests After: Claude writes the failing test, you approve, it writes the implementation The discipline transfer is real. After a week with the skill