Karpathy builds a YouTube clone in about 2 hours by talking to Claude
Andrej Karpathy, who joined Anthropic in May, says his only manual steps were an API key, a server and a domain name. The account comes from an employee of the company that makes the model.
Source published · In the Daily Brief of 2 November 2026
Filed under Agents, Large language models
Andrej Karpathy, a co-founder of OpenAI who joined Anthropic in May, wrote on Saturday that he had built HackerTube, a video site, in about two hours. He gave Anthropic’s Opus 5.5 model one task: write a YouTube clone from the videos recommended on Hacker News. The model downloaded the site’s comments, ran a cheaper model over them, removed spam and kept 40,000 comments that recommend a video. The result is 6,454 videos from 2007 to 2026 across 150 topics, with midpoint frames in place of uploaded thumbnails and recommendations stored in the browser, without accounts.
Karpathy said he no longer reads or writes code or runs terminal commands, and only talks to the model. His own work was to create a Google Cloud key, start a server and buy the domain. He then gave the model the server’s address and told it to deploy, secure and optimise the code.
The post reached 2,329 points on Hacker News, and a copy for books, HackerBooks, followed within a day. The time and the division of labour are his own account, and nobody has audited the code.