Beyond the Vibe, How far can we push It?, by Roger Johansson
This title could be clearer and more informative.Try out Clickbait Shieldfor free (5 uses left this month).
A developer with a distributed computing background shares the journey of building a JavaScript engine from scratch using 100% AI-generated code (zero manual lines). Starting from a single Codex prompt, the project evolved over months to pass ~93,500 of 94,000 ECMAScript spec tests and run real Express.js applications on .NET. Key insights include: using a 'runtime spy' debug function to give AI agents visibility into live program state, building a custom async test runner to handle crashing/freezing tests, automating bug fixes overnight via 'Ralph loops' (shell scripts that feed failing tests to AI agents and auto-commit fixes), and leveraging a custom profiler to let agents analyze performance. The AI unexpectedly invented a bizarre 'replay generator' approach for async/generators that passed tests but had completely wrong behavior, which led to discovering a cleaner IR-lowering architecture. The talk concludes with a demo of factorial.ai, an evolved tool for fully automated backlog fixing.