You asked about COVID-19
7 people built something like it. 1 is gone.
That is 14% of the ones whose fate we could settle, against 23% across the whole register.
| Launched | What it was | Today |
|---|---|---|
| 2020-01-01 | YCPostEra Medicinal Chemistry powered by Machine Learning · postera.ai | still up |
| 2022-01-01 | YCScout The smart testing platform that unlocks digital health at home. · scouthealth.com | still up |
| 2023-01-01 | YCScanbase The API for Diagnostic Test Analysis (COVID-19, FLU, RSV, STD,… · scanbase.com | still up |
| 2018-01-01 | We are using the gut microbiome to end cancer. · persephonebiosciences.com | still up |
| 2017-06-01 | Rapid, scalable diagnostic for SARS-CoV-2 and beyond · predxionbio.com | gone |
| 2017-01-01 | Next-generation mRNA platform to solve cancer, COVID and climate. · helixnano.com | still up |
| 2019-01-01 | YC1910 Multimodal AI Platform for Modality Agnostic Drug Discovery™ · 1910.ai | still up |
How this compares
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.