We are using Next.js + Vercel to build a site that integrates with Contentful and another third party rest API.

We make heavy use of ISR and chose to revalidate pages using revalidateTag

However there has never been an instance where this has worked reliably.

Discord and GitHub are awash with issues of revalidateTag just not working.

I've debugged the revalidateTag function right up until it makes a call into the Vercel API and after that I have no idea what goes on. If we use multiple tags or single tags it makes no difference. A page displaying the same data will show the old version on one and a new version on another.

I raised a support case with Vercel and haven't gotten a response.

Is anyone actually using the data cache in production and getting reliable revalidation?