Andrej Karpathy spent a Friday night annoyed at YouTube’s recommendations and a Saturday building a replacement. The result, published October 31, is a video site stocked only with clips that Hacker News commenters have recommended since 2007.
The numbers behind it are modest but concrete. Claude Opus 5.5 pulled the site’s comment archive, ran Claude Sonnet over it inside a Claude Code workflow to strip spam, and narrowed roughly 40,000 comments down to those recommending a video. That produced 6,454 videos spanning 150 topics, wrapped in a familiar browsing interface.
Three jobs a human still had to do
Karpathy’s own account of the build is the part worth reading. He wrote that he no longer does anything resembling traditional engineering, and that his manual contribution amounted to creating a Google Cloud API key, booting a virtual private server, and buying the domain.
Everything after that was instruction. He handed over the server address and asked for the code to be deployed, secured, hardened and optimized. The site now runs without user accounts, keeps recommendation state in the browser session, and offers a data export so anyone can hand the corpus to an agent and build their own version.
What the demo actually measures
A two-hour clone is not a business, and Karpathy presents it as a personal fix rather than a product. But it functions as a datapoint on how far a single practitioner can move with a coding agent and no team.
It also surfaces the limits. The work was well-specified, self-contained, and checkable by eye, a shape that coding agents handle far better than sprawling codebases with years of undocumented decisions.
