His father was also a noted architect whose work included St. John's Church in Bergen and Villa Fridheim in Krødsherad.

[2] Backer was educated at the Oslo National Academy of the Arts under the supervision of Herman Major Schirmer and the Royal Institute of Technology in Stockholm, from which he graduated in 1915.

He served as an apprentice with several notable contemporary architects in Norway, including Harald Hals (1876–1959) and Ole Sverre (1865–1952), as well as Arnstein Arneberg and Magnus Poulsson.

[5][6] Backer was responsible for several notable Scandinavian works including the Skansen restaurant (1926–1927) and Ekebergrestauranten (1927–29) in Oslo, and the first high-rise office building in the city.

His Skansen restaurant was the first modernist building in Norway, earning Backer lasting fame as a pioneer of Scandinavian Functionalism.