Denis Firsov is a Research Engineer at Guardtime since 2019 and also serves as a Researcher at TalTech University. Firsov previously worked as a Postdoctoral Researcher at the Computational Logic Center at the University of Iowa from 2016 to 2018 and as a Lecturer at Estonian Information Technology College from 2012 to 2016. Firsov began a career in academia as a Junior Researcher at the Institute of Cybernetics at Tallinn University of Technology between 2011 and 2016, following roles as a Software Developer at Attitude OÜ and Majandustarkvara OÜ from 2010 to 2011 and 2009 to 2010, respectively. Firsov holds a Doctor of Philosophy (Ph.D.) in computer science, focusing on logics, constructive mathematics, compiler construction, and parsing from TalTech – Tallinn University of Technology, where a Master of Science in Information Technology was also earned. Earlier education includes studies at Estonian Information Technology College and Russian Gymnasium of Mustvee.