Julien specialises in international commercial arbitration and investment treaty arbitration notably in the construction, energy, hospitality, mining, and oil and gas sectors.

He acts as counsel, chairman of the arbitral tribunal, co-arbitrator or sole arbitrator. He has extensive experience of complex arbitration in Europe, the Middle East and Africa under the rules of the most prominent arbitral institutions, and has also considerable experience in sports arbitration before the CAS/TAS.

Julien is the Secretary General of the International Academy for Arbitration Law, is a former Vice-Chair of the IBA Arbitration Committee, a former co-chair of the ASA below 40, the CFA 40 and of the IBA Arb40 subcommittee.

Julien is also a former Counsel at the Secretariat of the International Court of Arbitration of the ICC.

He is ranked among France's leading international arbitration lawyers by Chambers & Partners, and features in The Legal 500's Arbitration Powerlist. He is also recognised in GAR, Who's Who Legal and Décideurs Leaders League.

He is the author of several articles including four books notably the critically acclaimed “The ICSID Convention, Regulations and Rules – A Practical Commentary” (Edward Elgar Publishing, 2019), which has been described as “an impressive piece of scholarship” and “anyone interested in this field will certainly want to add it to their library” as well as “Provisional and Emergency Measures in International Arbitration” (Edward Elgar, 2023) described as “an invaluable contribution”.

He teaches international arbitration law in Masters programs at French universities and abroad.

He has joined HFW in May 2024 to support and develop the growing Arbitration practice.

Julien is a member of the Paris Bar and is fluent in French and English.