Joseff is originally from Llandovery and was educated at Llandovery College. A keen rugby player, he went to Loughborough University to study English, representing the university rugby team and graduating with First Class Hons. Joseff completed the Graduate Diploma in Law at Cardiff University, where he was awarded the Prince of Wales Scholarship from Grays Inn, allowing him to study and then complete the Bar Professional Training Course (‘BPTC’) at Cardiff Law School. Joseff successfully completed his pupillage and accepted a tenancy with Chambers in September 2018. He accepts work across Chambers areas of practice.
During his Bar studies, he won the Norman Tapp Memorial Prize and was a DuCann Prize Finalist, both from Grays Inn. He is also a Grays Inn Goddard Scholar.
Before obtaining pupillage, he undertook internships in New Delhi, India and Kathmandu, Nepal in the field of human rights.
Joseff is a Welsh speaker.