In April 2015, he was appointed as the official spokesperson of the Ministry of External Affairs of India to head its Public Diplomacy divisions at New Delhi, succeeding Syed Akbaruddin.

[9] In December 2019, Swarup took charge as Secretary (West) in the Ministry of External Affairs, looking after relations with Europe, Central Asia as well as the United Nations system.

[12][13] He also served in Ankara, Washington D.C., Addis Ababa, London, Pretoria and as Consul General in Osaka-Kobe, Japan.

Swarup's debut novel, Q & A, tells the story of how a penniless waiter in Mumbai becomes the biggest quiz show winner in history.

It was optioned for a film by the BBC and Starfield productions and John Hodge, who has been commissioned to write the screenplay.

He has written for TIME, Newsweek, The Guardian, The Daily Telegraph (UK), Outlook magazine (India) and Libération (France).

On 21 September 2010, the University of South Africa (UNISA) conferred the degree of Doctor of Literature & Philosophy (honoris causa) on Swarup at a graduation ceremony in Pretoria.

On June 18, 2020, Montreal-based Concordia University conferred an Honorary Doctorate on Swarup for literary excellence and dedication to diplomacy.