Launch HN: Cardboard (YC W26) – Agentic video editor

Hey HN - we're Saksham and Ishan, and we’re building Cardboard (https://www.usecardboard.com). It lets you go from raw footage to an edited video by describing what you want in natural language. Try it out at https://demo.usecardboard.com (no login required). Also, there’s a demo video at: https://www.usecardboard.com/share/fUN2i9ft8B46 People sit on mountains of raw assets - product walkthroughs, customer interviews, travel videos, screen recordings, changelogs, etc. - that could become testimonials, ads, vlogs, launch videos, etc. Instead they sit in cloud storage / hard drives because getting to a first cut takes hours of scrubbing through the raw footage manually, arranging clips in correct sequence, syncing music, exporting, uploading to a cloud storage to share, and then getting feedback on WhatsApp/iMessage/Slack, then re-doing the same thing again till everyone is happy. We grew up together and have been friends for 15 years. Saksham creates content on socials with ~250K views/month and kept hitting the wall where editing took longer than creating. Ishan was producing launch videos for HackerRank's all-hands demo days and spent most of his time on cuts and sequencing rather than storytelling. We both felt that while tools like Premiere Pro and DaVinci are powerful, they have a steep learning curve and involve lots of manual labor. So we built Cardboard. You tell it to "make a 60s recap from this raw footage" or "cut this into a 20s ad" or "beat-sync this to the music I just added" and it proposes a first draft on the timeline that you can refine further. We built a custom hardware-accelerated renderer on WebCodecs / WebGL2, there’s no server-side rendering, no plugins, everything runs in your browser (client-side). Video understanding tasks go through a series of Cloud VLMs + traditional ML models, and we use third party foundational models for agent orchestration. We also give a dropdown for this to the end user. We've shipped 13 releases since November (ht