Andrej Karpathy builds HackerTube in a weekend with Claude, from 20 years of Hacker News comments
Claude Opus 5.5 narrowed 43 million comments down to 6,454 frequently recommended videos. A second site took three minutes with Claude Code.
Andrej Karpathy, an OpenAI co-founder who now works as a researcher at Anthropic, says he built a curated video site called HackerTube over a weekend using Claude Opus 5.5. Claude filtered 43 million comments from 20 years of Hacker News and narrowed them down to 6,454 videos that users there keep recommending. Writing on X, Karpathy called the result a "significantly better viewing experience" than YouTube's own recommendations. The site needs no login. It shows one frame from the middle of each video instead of optimized thumbnails, and it stores state locally in the browser. Right afterward, Karpathy built a second site, TristanTube, which he said was "one-shotted with Claude Code in 3 minutes." It holds 47,000 videos drawn from a list of YouTube channels compiled by Tristan Hume. Karpathy says Claude Code did nearly all the work, from analyzing the data to setting up the server. His only manual steps were getting a Google Cloud API key, renting a server and buying the domain. He says projects that used to take weeks can now be done in a few hours. This is one developer's account of a hobby project, not a controlled measurement of productivity.