JSSE: A JavaScript Engine Built by an Agent
Summary
A solo experiment demonstrates building a complete JavaScript engine from scratch using an autonomous coding agent (Claude Code) in Rust. The project passes 100% of non-staging test262 tests and reveals the power and limits of agent-driven software development, including planning, prompt design, and long-running task management. The piece also includes performance comparisons, costs, and practical lessons for AI-assisted engineering and automation workflows.