From 1706 to 1709 he was at the private observatory of Baron Bernhard Friedrich von Krosigk (1656–1714) Berlin; in the following years followed various posts in Russia and Silesia.

On 16 December 1722 his son Johann Friedrich Wilhelm Wagner was born in Hildburghausen.

[1] In 1730 Wagner became Professor of Architecture at the Akademie der Künste in Berlin, and in 1735 Librarian of the Academy of Sciences.

In 1740 after the death of Christfried Kirch he was named as his successor as Director of Berlin Observatory - a post which he held for the rest of his life.

The almanac calculation at the Observatory am Observatorium took so much of his time that his son undertook some of his work in teaching at the Akademie der Künste.