I am working on a site. I got this from a client to be redesigned. The old design was made by some other agency. Once I was done, and changed old DNS records to the new server and went live with the new design, everything worked OK. Except, for old users of the site.
All old users couldn't see the new design. I did everything I could to force the browser to forget cache by using HTTP Headers, .httaccess etc. Nothing worked.
I later found that the old design was built on PWA technology. Progress Web Apps which can be installed as an app on the device. And this app used something called worker cache to store static files in the Cache Storage and Application cache.
Now for some reason, old users' browsers are not willing to forget that cache at all. Looks like the browser isn't even hitting my new server / DNS settings for the new design. It just takes the content from the worker/application cache and displays the old site.
I can't ask users to clear their cookies or cache, or uninstall the app individually. How can I get rid of this cache from old users' browsers so that the new design is working on those devices too?
Any ideas?