How AI Coding Agents Actually Work: An Architectural Guide [2026]

When Terence Tao — one of the most celebrated mathematicians alive, a Fields Medalist, someone who has spent decades pushing the boundaries of human reasoning — sat down last week to port 25-year-old Java applets to modern JavaScript, he didn&rsquo;t write a single line of code by hand. He described what he wanted to an AI agent, reviewed the output, and in a few hours had working applets that had…