Amman has litigated before state and federal courts and arbitral bodies in Los Angeles, New York, Toronto, Ottawa and Montreal, and has advised on the foreign aspects of litigation pending before Moscow courts, Swiss Courts, English Courts and New Zealand Courts. He has practiced in both common law and civil law jurisdictions and has represented clients in both English and French. He also speaks Hindi and Urdu, and uses his global experience to obtain the best results for clients through a multijurisdictional approach to litigation.

In addition to complex commercial, sports and entertainment-related litigation Amman advises on delicate personal matters in which his clients are the target of reputational attacks and smear campaigns, cyber fraud and data privacy related issues. He has represented multinational family offices, entrepreneurs and founders, a Russian billionaire, the fifth largest bank in the United States and a number of other companies and national brands.

Amman is admitted in California, as a Barrister & Solicitor in Ontario, Canada and as a Foreign Registered Solicitor in England & Wales. International disputes he has handled include complex commercial claims, injunctions and restraining orders, judgment collection, maritime, aviation and insurance, cargo claims, film and television distribution, human rights, and NAFTA-related issues. He also has a published decision from the Federal Court of Canada regarding international cargo claims: Canusa Systems v. Canmar Ambassador, 146 F.T.R. 314 (1998) and a published decision on a novel issue of California employment law in Arechiga v. Dolores Press, Inc., 192 Cal. App. 4th 567 (2011). Amman has been an international litigator since 1997.