I have a multivendor website based on magento 2.1.5. with multistore (Arabic/English)
the requirement is to upgrade to latest version 2.2.6 while keeping functionality and assure that upgrade is possible in future as well.
I would needed ssh details and admin details to upgrade the latest version, If you have any customization within core files than please share. I can do this today. Waiting for your response. Thanks Viren