You asked about Recommendation System
50 people built something like it. 4 are gone.
That is 8% of the ones whose fate we could settle, against 23% across the whole register. 1 were acquired.
| Launched | What it was | Today |
|---|---|---|
| 2023-01-01 | AI Powered Product Discovery · rubberduckylabs.io | gone |
| 2023-04-12 | librarian-ai.com | gone |
| 2022-01-01 | AI-native operating system for home service businesses · broccoli.com | still up |
| 2020-06-01 | YCLuminai Luminai is the AI platform for Health System Operations. · luminai.com | still up |
| 2021-07-22 | readow.ai | still up |
| 2023-10-06 | whattoreadafter.xyz | gone |
| 2023-06-01 | AI Operating System for Private Market Investors · vectorshift.ai | still up |
| 2026-06-01 | Mass-produced AI strike systems and Counter-UAS · isengardindustries.com | still up |
| 2019-01-01 | Bunkerhill is the agentic AI platform for health systems · bunkerhillhealth.com | still up |
| 2021-01-01 | YCPer Diem The AI operating system for restaurants · tryperdiem.com | still up |
| 2023-01-01 | YCMetal Metal is an AI-driven operating system for fundraising · metal.so | still up |
| 2024-06-01 | YCmdhub AI-native operating system for behavioral health clinics. · mdhub.ai | still up |
| 2025-09-01 | YCLexi AI Operating System for Legal Teams · getlexi.io | still up |
| 2025-01-01 | AI powered operating system for distributors and OEMs · salespatriot.com | still up |
| 2020-06-01 | AI-native Operating System for Enterprise Ecommerce Companies · hypotenuse.ai | still up |
| 2024-01-01 | YCCarma The AI Operating System For Modern Fleets. · joincarma.com | still up |
| 2024-09-01 | YCArchil The high-performance file system that connects AI to data · archil.com | still up |
| 2024-06-01 | Capitol: the sovereign operating system for intelligence. · capitol.ai | still up |
| 2022-01-01 | AI-driven HVAC control system for improved energy performance · axross.co | still up |
| 2023-05-16 | heyollie.ai | unverified |
| 2025-01-01 | YCScout AI-powered student information system for K-12 schools · scoutforschools.com | still up |
| 2025-09-01 | YCZavo AI Operating System for Restaurants · zavopay.com | still up |
| 2026-06-01 | The AI-powered operating system for radiology networks · avocasystems.com | still up |
| 2026-01-01 | Modular AI-Commanded Drones for Defence · seeing-systems.com | still up |
| 2024-01-01 | The AI operating system for commodity operations · commodityai.io | still up |
| 2022-01-01 | The System of Action for Conversation Data · spinach.ai | still up |
| 2021-06-01 | Increasing restaurant profitability through our AI Operating System · bytekitchen.io | acquired |
| 2026-01-01 | A premier AI-native law firm & legal operating system for Startups. · vectorlegal.com | still up |
| 2026-06-01 | Autonomous AI defense system for cyber attack · nebusec.ai | still up |
| 2022-06-01 | Operating system for HR in the AI era · aragorn.ai | still up |
| 2026-01-01 | AI operating system for mega-scale satellite networks. · constellation.space | still up |
| 2026-06-01 | YC6thSense Nervous System for Physical AI · 6thsense.dev | still up |
| 2023-01-01 | YCRetape AI Operating System for Debt Settlement · retape.ai | still up |
| 2024-06-01 | Java-native multi-agentic AI operating system for enterprise · redouble.ai | still up |
| 2024-09-01 | YCCanvas Building AI systems that improve from experience. · canvas.inc | still up |
| 2025-01-01 | YCDalus AI-Powered Hardware System Design Software · dalus.io | still up |
| 2023-01-01 | AI-native operating system for analytics teams · turntable.so | gone |
| 2025-06-01 | YCFulcrum The agentic debugger for AI systems · fulcrumresearch.ai | still up |
| 2026-06-01 | YCMireye Infrastructure for Physical World AI Agents · mireye.com | still up |
| 2026-06-01 | The AI Operating System for Auto Shops. · trycarsignal.com | still up |
| 2026-01-01 | AI operating system for commercial loans · proximitty.ai | still up |
| 2026-01-01 | YCAutoSitu The AI operating system for the built world · autositu.com | still up |
| 2026-01-01 | YCTepali AI operating system for modern medspas · tepali.com | still up |
| 2025-09-01 | YCBravi The AI operating system powering home services businesses · bravi.app | still up |
| 2024-09-01 | AI Operating System for Pre-construction · permitportalapp.com | still up |
| 2024-01-01 | AI system design tools for dev teams · agenticlabs.com | still up |
| 2022-06-01 | AI Models for GIS · buntinglabs.com | still up |
| 2021-06-01 | YCMiniloop AI workflow engine for reliable systems · miniloop.ai | still up |
| 2018-06-01 | Synkrino's AI, SATIS is a powerful, unbiased discovery system for… · synkrino.bio | still up |
| 2026-06-01 | AI Operating System for Wholesale Distribution · whitespacehq.ai | still up |
| 2024-01-01 | YCScritch AI operating system for veterinary care · scritchai.com | still up |
How this compares
Y Combinator reports its own outcomes, including acquisitions. The other two are judged by asking the domain, so they are not measured the same way and are never averaged together.
The register re-probes every domain it holds. Some that answered last month stop answering. We send that list — what went quiet, and what it was — once a month. Nothing else.
How this was made. Show HN entries are every post from 2021 to 2023 with at least five points that linked to its own domain; code hosts and free hosting are excluded, because a repository outlives the effort behind it. Product Hunt entries needed 100 votes — a far higher bar, so they are the promoted top slice rather than a like-for-like sample. Both are judged by asking the domain whether it still answers: gone means it no longer resolves, refuses the connection, serves a parking page, or says plainly that it shut down. An HTTP error is not counted as gone — a server answering 404 is one somebody still pays for, and an audit of 25 gone-calls found two such sites alive with only a moved homepage. Y Combinator entries use the status YC publishes itself, which is why only those can say acquired. Squatted domains — a lapsed name now serving somebody else's site — are not detected, so these figures run slightly low.