Skew protection in Vercel (via) Version skew is a name for the bug that occurs when your user loads a web application and then unintentionally keeps that browser tab open across a deployment of a new version of the app. If you’re unlucky this can lead to broken behaviour, where a client makes a call to a backend endpoint that has changed in an incompatible way.
Vercel have an ingenious solution to this problem. Their platform already makes it easy to deploy many different instances of an application. You can now turn on “skew protection” for a number of hours which will keep older versions of your backend deployed.
The application itself can then include its desired deployment ID in a x-deployment-id header, a __vdpl cookie or a ?dpl= query string parameter.
Recent articles
- Claude can write complete Datasette plugins now - 8th October 2025
- Vibe engineering - 7th October 2025
- OpenAI DevDay 2025 live blog - 6th October 2025