[1] Cocceji studied law with his father Heinrich von Cocceji, received his doctorate in 1699 and embarked on a three-year educational trip through Italy, France, England and Holland.

In 1702, after his European travels, he became a professor of law at Viadrina University in Frankfurt (Oder).

By 1723 he was Kammergerichtspräsident (president of the Kammergericht) and from 19 September 1731 to 1737 he served as the president of the Oberappellationsgericht zu Berlin (Court of Appeal in Berlin), the highest court of Prussia.

[2] In 1738 and 1739, Cocceji was chairman of the Prussian justice department, before he was made Großkanzler (grand chancellor) in 1747.

King Frederick II of Prussia appointed Cocceji to lead the legal reorganization of annexed Silesia.