Between 1966 and 1990 Spinei was a researcher at the A.D. Xenopol Institute of History and Archaeology of the Romanian Academy in Iași. The archaeology section split in 1990, forming the Iași Institute of Archaeology (likewise under the aegis of the Romanian Academy), in which Spinei continued his work until 2012.[1] He was the director of the Iași Institute of Archaeology between 2003 and 2011, and has been an Honorary Director since 2014. Since 2015 he has been a corresponding member of the German Archaeological Institute.[1]
Between 2001 and 2015 Spinei was a corresponding member of the Romanian Academy; he became a titular member of the Academy on July 5, 2015, and was elected vice president on November 27, 2015.[3][4]
He is member of several editorial boards, including Arheologia Moldovei, Dacia, Historia Urbana, Studii și Cercetări de Istorie Veche și Arheologie, Res Historica, and Acta Euroasiatica; he also founded and coordinates several academic book series published by the Alexandru Ioan Cuza University and the Romanian Academy.[1][5][6]
Since 2012 he has been a member of the Commission for History and Cultural Studies of the Romanian National Council for Attesting Titles, Diplomas and University Certificates.[7]
The Romanians and the Turkic Nomads North of the Danube Delta from the Tenth to the Mid-Thirteenth Century, Brill, Leiden–Boston, 2009, ISBN978-90-04-17536-5.
In French
Les Princes Martyrs Boris et Gleb. Iconographie et Canonisation, Archaeopress, Oxford, 2011, ISBN978-1-4073-0902-6.
Mongolii și românii în sinteza de istorie ecleziastică a lui Tholomeus din Lucca / Les Mongols et les Roumains dans la synthèse d’histoire ecclesiastique de Tholomeus de Lucca, Editura Universității “Al. I. Cuza”, Iași, 2012, ISBN978-973-703-737-4.