He is co-founder, host and executive producer of Radio Ambulante, an award-winning Spanish language podcast distributed by NPR.

His most recent story collection, The King is Always Above the People, was long-listed for the National Book Award in 2018, and won the 2019 Clarke Prize in Fiction.

Alarcón's debut novel, Lost City Radio, was published 2007, and has been translated into Spanish, Portuguese, French, German, Dutch, Greek, Italian, Serbian, Turkish, and Japanese.

In 2009, he published a collection of short stories, El rey está siempre por encima del pueblo (The king is always above the people), and the following year, "Ciudad de payasos", a graphic novel adapted from his 2003 story City of Clowns, with illustrations by Peruvian artist Sheila Alvarado.

In 2011, he co-founded Radio Ambulante with his wife Carolina Guerrero, along with Camila Segura, Martina Castro and Annie Correal.