Viswanathan heads the finance and infrastructure (projects) practice at Cyril Amarchand Mangaldas. He has rich experience in project finance, infrastructure and banking and advises leading corporates, banks and financial institutions. His key areas of specialisation include structured finance, debt restructuring, insolvency and distressed asset sales. He has acted on a number of landmark transactions, including advising Indian lenders on the restructuring of the Dabhol Power Project (2001–2005).

He is currently involved with leading banks and asset reconstruction companies in working through the initial cases under the new Insolvency and Bankruptcy Code, 2016.

Viswanathan has been included amongst the top finance lawyers in India by several leading international legal publications including Chambers Global 2012 and Who’s Who Legal. Chambers Asia Pacific 2016 states that ‘L. Viswanathan is revered by sources as “the best projects lawyer in India”. He brings “extraordinary knowledge and his understanding of all aspects of projects in unmatched.” ’ The Legal 500 (2017) states that ‘L Viswanathan has significant expertise in the oil and gas, renewable energy and infrastructure sector.’