Sam Kaislaniemi defended his PhD in December 2017 (his thesis, Reconstructing Merchant Multilingualism: Lexical Studies of Early English East India Company Correspondence, is available as a pdf). He works on early modern English letters, being mostly interested in code-switching, and more recently in letterlocking. Sam is a member of the STRATAS project (2016-2019), in which he is trying to develop a hierarchy of the philological reliability of editions of historical correspondence. He is also a co-compiler of the Corpora of Early English Correspondence (CEEC). If you see him in a British archive, buy him a cup of tea. If you see him on Twitter, tell him to get off the internet and go and read a book or something.