Harness Engineering: From AI-Assisted to AI-Driven, What Is Software Engineering Undergoing?

What happens when a team ships a million lines of code without writing a single line by hand? Editor’s Note: This article is based on verified engineering blogs from OpenAI, Anthropic, and Mitchell Hashimoto (2025–2026). All references are linked at the end. Editor’s Note: This article is based on verified engineering blogs from OpenAI, Anthropic, and Mitchell Hashimoto (2025–2026). All references are linked at the end. In February 2026, OpenAI engineers revealed they had shipped a million-line