After graduation, Granin began working as a senior engineer at an energy laboratory, and shortly after war broke out, he volunteered to fight as a soldier.

[3] Granin served as a board member of the Leningrad Union of Writers, and won many medals and honors including the State Prize for Literature in 1978 and Hero of Socialist Labor 1989.

[3] According to the Great Soviet Encyclopedia: "The main theme of Granin’s works is the romance and poetry of scientific and technological creativity and the struggle between searching, principled, genuine scientists imbued with the communist ideological context and untalented people, careerists, and bureaucrats (the novels Those Who Seek, 1954, and Into the Storm, 1962)".

In 1979, he published Blokadnaya kniga (translated as A Book of the Blockade), which mainly revolves around the lives of two small children, a 16-year-old boy and an academic during the Siege of Leningrad.

[5] Written together with Ales Adamovich, the book is based on the interviews, diaries and personal memoirs of those, who survived the siege during 1941–44.