Joshua's primary focus is international arbitration and he has been involved in disputes covering a number of sectors including mining, energy, automotive, commodities, insurance, telecommunications and infrastructure. He also has experience representing clients in matters concerning state responsibility and public international law.

He has been involved in cases under the rules of various arbitral institutions, including the ICC, FCCC, LCIA, PCA and SCC, plus experience of ad hoc proceedings under the UNCITRAL rules and the Swedish Arbitration Act. He has gained diverse and high profile experience working for leading law firms in both civil and common legal systems.

Joshua serves on the Peer Review Board of ICSID Review — Foreign Investment Law Journal and was appointed by the ICCA Executive Body to serve on the ICCA Publications Advisory Board.  He was also appointed to the International Centre for Dispute Resolution Young & International Global Advisory Board and previously served as a Vice Chair of the International Arbitration Committee of the American Bar Association's Section of International Law.

Joshua co-authored a chapter on political risk insurance and investment arbitration that was recently published in an arbitration treatise titled International Investment Law.  He has also published articles in leading arbitration publications such as "GEA v. Ukraine and the Battle of Treaty Interpretation Principles Over the Salini Test" in Arbitration International and co-authored the "Young ICCA Guide on Arbitral Secretaries".

He frequently speaks on issues relating to international arbitration.

Joshua was identified as being among the world's leading arbitration specialists under 45 to be listed in Who's Who Legal: Arbitration - Future Leaders 2017.