You asked about Recommendation System
35 people built something like it. 35 are gone.
That is 100% of the ones whose fate we could settle, against 23% across the whole register.
| Launched | What it was | Today |
|---|---|---|
| 2009-06-01 | FanChatter aggregates, amplifies and empowers fan content on every… · fanchatter.com | gone |
| 2023-01-01 | AI Powered Product Discovery · rubberduckylabs.io | gone |
| 2022-05-23 | getnora.page | gone |
| 2022-05-20 | lettertribe.com | gone |
| 2023-04-12 | librarian-ai.com | gone |
| 2023-10-06 | whattoreadafter.xyz | gone |
| 2023-04-03 | pubnix.pink | gone |
| 2022-11-25 | search.rye.com | gone |
| 2021-04-01 | cfs.stokeo.com | gone |
| 2018-01-01 | Next-gen blood testing to provide 1000x more data to pharma companies · correliabio.com | gone |
| 2022-04-20 | corise.com | gone |
| 2022-01-01 | The operating system for factory production lines · aisupervision.com | gone |
| 2023-02-03 | getproduct.help | gone |
| 2022-08-22 | jamsync.io | gone |
| 2022-05-27 | personalfilesystem.org | gone |
| 2020-01-01 | Multiverse is a web-based game creation system inspired by Dungeons &… · playmultiverse.com | gone |
| 2018-06-01 | Operating systems for biology labs · radix.bio | gone |
| 2021-06-01 | YCAlgofi Building the new financial system · algofi.org | gone |
| 2023-04-20 | designducky.ai | gone |
| 2021-03-08 | caint.casa | gone |
| 2021-07-13 | wasi.fyi | gone |
| 2022-08-02 | mypelotonclasses.com | gone |
| 2006-06-01 | Community-curated catalogs for product recommendations · zanbazaar.com | gone |
| 2011-06-01 | YCPhoneSys The Phone System for Sales Teams. · pingm.net | gone |
| 2023-01-01 | AI-native operating system for analytics teams · turntable.so | gone |
| 2021-01-01 | YCPlatypus The Distributed Data Operating System · getplatypus.com | gone |
| 2015-06-01 | Building the lowest-power silicon for embedded deep learning and… · remicro.com | gone |
| 2012-06-01 | YCViacycle viaCycle makes simple, inexpensive bicycle sharing systems that allow… · viacycle.com | gone |
| 2013-06-01 | YCAmulyte Remote monitoring & activity tracking system for seniors. · amulyte.com | gone |
| 2013-06-01 | Replacing the paper restaurant menu with an interactive experience at… · buttersystems.com | gone |
| 2012-06-01 | YCProfig The phone system for businesses. Manage everything from your company… · profig.com | gone |
| 2017-01-01 | YCCowlar Fitbit for dairy cows. Farms use cowlar's alerts & recommendations to… · cowlar.com | gone |
| 2018-06-01 | Democratizing gene therapy by reinventing its manufacturing and… · perception.bio | gone |
| 2021-01-01 | YCLunatic Operating System for server-side apps · lunatic.solutions | gone |
| 2021-01-01 | Building the operating system for diagnosis. · bewelldigital.com | gone |
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.