Joshua began his studies at Chetham’s with Gitte Marcusson, Richard Davis and Katherine Baker, during which he became Principal Flute of the National Youth Orchestra of Great Britain. He was awarded a full scholarship from the Royal Academy of Music where he studied with Michael Cox completing his BMus in 2014. While a student of the school Joshua spent a year studying with Jacques Zoon at the Haute Ecole de Musique Genève where he also became principal flute of the Gustav Mahler Jugendorchester.
Joshua has guested as Principal Flute with the London Symphony Orchestra, London Philharmonic Orchestra, Academy of St Martin in the Fields, BBC Symphony Orchestra, Swedish Radio Symphony Orchestra, Bergen Philharmonic, Malaysia Philharmonic Orchestra, Royal Philharmonic Orchestra, BBC Philharmonic, Halle, Opera North, Royal Ballet Sinfonia, BBC Wales, Aurora Orchestra, Welsh National Opera, Royal Northern Sinfonia, John Wilson Orchestra, London Sinfonietta, London Mozart Players, Orchestra of St John's and Ensemble 360. Solo highlights include Buckingham Palace, Bridgewater Hall and National Concert Hall Dublin.
Joshua is the former Principal Flute of the RTÉ Concert Orchestra, Dublin (2015–17), a tutor of flute at the Royal Northern College of Music, and most recently became Principal Flute with Sydney Symphony Orchestra.