Dexter saw the daylight in 2017 at Cito, with some financial help from the Dutch ministry of education, culture, and science. Dexter is developed by Gunter Maris, Timo Bechger, Jesse Koops, and Ivailo Partchev.

Timo and Gunter work at Metior, a consulting firm and research center specialized in psychometrics for assessment and learning.

Ivailo and Jesse work at Cito, the Dutch National Institute for Educational Measurement.