You asked about Developer Tools
Nobody in the register described anything this way.
| Launched | What it was | Today |
|---|---|---|
| 2021-01-01 | YCUiflow No-code platform for enterprise software companies · ycombinator.com | acquired |
| 2021-06-01 | YCArengu Build frictionless signup flows in minutes · arengu.com | acquired |
| 2021-01-01 | Supercharge your mobile apps · emergetools.com | acquired |
| 2021-06-01 | Eliminate Cloud Waste. Attribute and Track Savings. Engage Engineers. · cloudthread.io | acquired |
| 2021-01-01 | YCAvenue Observability platform for operations teams · avenue.app | acquired |
| 2021-01-01 | Build better computer vision models by building better datasets · segments.ai | acquired |
| 2021-06-01 | YCSatsuma Reliable blockchain indexing & querying for web3 engineering teams. · satsuma.xyz | acquired |
| 2021-06-01 | YCKeyri Secure fraud prevention and authentication platform for developers · keyri.com | acquired |
| 2021-01-01 | A faster and more collaborative alternative to Jira for remote teams · kitemaker.co | acquired |
| 2021-01-01 | Open source continuous profiling software to debug performance issues · pyroscope.io | acquired |
| 2021-01-01 | YCFriz AI Social Media Manager · usefriz.com | acquired |
| 2021-06-01 | YCWarrant Authorization and access control as a service. · warrant.dev | acquired |
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.