Born in San Sebastián in 1963, Iriarte began a career in journalism at the local radio station Loiola Herri Irratia at the age of eighteen, while she was a Law student at the University of the Basque Country.[3]
In 1986, Iriarte joined the Basque public broadcast service EITB, where she was the presenter and editor of the ETB 1 news program Gaur Egun until 2009.[4] Iriarte was also an editor and presenter on election results programmes, and political debate programmes Ados?, Gau-on and Azpimarra.
In 2016, Iriarte entered politics as a candidate for Member of Parliament at the 2016 Basque regional election: Iriarte was placed second in EH Bildu's list of candidates for the constituency of Gipuzkoa.[5] Iriarte eventually headed the coalition's list after the Election Commission, upheld by the Constitutional Court of Spain, invalidated Arnaldo Otegi's candidature due to the Bateragune Case.[6] After Iriarte was elected Member of Parliament, she was designated spokesperson for EH Bildu, and she was the coalition's candidate for Lehendakari at the investiture session.[7]