In 1722 he was enlisted in the service, and in 1724 he was appointed page of the chamber to Princess Anna Petrovna, the wife of the Duke of Holstein Karl-Friedrich.
Peter III, who appreciated Devier's service to his parents, granted him the orders of St. Anna, Saint Alexander Nevsky, and Andrew the First-Called, and elevated him to general-in-chief on February 9, 1762.
On the day of Catherine's coup, June 28, 1762, Count Devier was sent by Peter III to Kronstadt to enlist the support of the garrison, but upon arriving at the fortress, he immediately surrendered to the envoy of Catherine II, to Admiral I. L. Talyzin and swore an oath to the Empress.
As in the case of the offspring of other favorites of Peter III, who were disgraced, the Devier family under Catherine was repeatedly prosecuted and eventually fell into poverty.
According to P. V. Dolgorukov, Deviers had the reputation of "the main leaders of robbery in the Kharkiv and Voronezh provinces".