Kahlos was a research fellow at the Helsinki Collegium for Advanced Studies and a researcher in the Academy of Finland Centre of Excellence (2011–2021). She was a visiting fellow at the Käte Hamburger Kolleg at Ruhr Universität Bochum in 2019. In 2001, she was a visiting fellow at the Friedrich Meinecke Institut at the Freie Universität Berlin. In 2021–2022 she was a visiting fellow at Clare Hall, University of Cambridge. Currently, Kahlos is principal researcher at Centro de Estudos Clássicos, University of Lisbon.
Kahlos has written four books covering various topics of late antique history and religion, most recently Religious Dissent in Late Antiquity, published by Oxford University Press (2020), described as "a welcome addition to the scholarship on late antique Christianity".[3] She published the monograph Forbearance and Compulsion: The Rhetoric of Tolerance and Intolerance in Late Antiquity, in 2009. She has edited or co-edited six books, most recently Slavery in the Late Antique World, 150-700 CE (Cambridge University Press 2022).[4]
