Consider using redirects or new vhost instead of transparent proxy
Is there an easier way to route the wikis rather than having rules with 1800 or in the traefik file ? How to untangle the archive from the running app ? If we could catch 404, we could have an approach similar to blog archive where the few migrated blogs are redirected to wordpress. Or just continue to add directories with redirect foreach new wiki. Wikijs by default redirects /wikiname to /en/wikiname. Therefore the wiki in wikijs will end up with a different final url anyway. At that point, why not using a different base url (e.g. docs.epfl.ch instead of wiki.epfl.ch) for the new engine ?
A nice way to do this would also be to have a tiny app with a redis DB that generates the redirects by simply pulling the url from the DB based on the first element of the path.