The author shares their experience of creating Beep, a fictional programming language, in collaboration with the AI tool Claude Code. Through detailed examples, they explore features like lexical and dynamic scoping, as well as the AI's assistance in solving complex programming challenges and refactoring code.

• Claude Code built a working interpreter for "Beep," a made-up language with unusual scoping rules, largely autonomously from a spec.
• It handled the tricky distinction between lexical and dynamic scoping correctly, including edge cases the author hadn't fully worked out themselves.
• The AI could refactor and extend the codebase iteratively, adjusting to new requirements without breaking existing functionality.
• The author frames this as evidence that Claude Code is useful for genuine software design/problem-solving, not just boilerplate code generation.