European Union (and some states connecting with the same infrastructure, like Switzerland), have standardized formats as well as defined CAs that provide certificates for "qualified" signatures, which have the same legal weight as if you had a printed document with physical signature.
DocuSign supports those mainly through some interop connections where, for example, a qualified signature vendor provides an API that DocuSign can use to sign the document.
You are right, that is precisely the route we will also have to take for certain regions. For example in India, there are only 3 entities that are authorized by the government to enable Aadhaar based e-signature. We will have to integrate with any of those in order to be compliant. We have already started working in this direction.
More than aadhar enabled signatures, India has pfx based digital signature system in place which is legally acceptable as good as a physical hand signature.
DocuSign supports those mainly through some interop connections where, for example, a qualified signature vendor provides an API that DocuSign can use to sign the document.