Sadi served as the executive director of Delta Life Insurance Company Ltd, and later founded a socio-political organization named Centre for Democratic Practice, dedicated towards fostering democracy and national consciousness and consensus in Bangladesh.

The youngest son of Late Dewan Mohammad Mamun Chowdhury and Syeda Zebunnessa Chaudhurani, Sadi was born in Nabiganj Upazila, Habiganj District, Sylhet on 10 May 1942.

Struck by his fearlessness and valor, the Commander in charge of the training camp, Brigadier General Watke, offered Sadi a position in the armed forces.

[2] Post-War Immediately after liberation, Sadi was made honorary commander of the Shanti Rakkhi Bahini in Sylhet by the fragile government of the newborn country for restoration of law and order and maintaining peace.

[4] Sadi had been a very active member of the Students Union of Bangladesh Awami League during Sheikh Mujibur Rahman's call for independence from Pakistan.

[4] In 1972, Mahbubur Rob Sadi, as left-wing commander took part in the formation of Jatiyo Samajtantrik Dal together with socialist political activists, military officers and pro-Awami League top ranking student leaders.

[2][6] In later years Sadi founded a socio-political organization named Centre for Democratic Practice, dedicated towards fostering democracy and national consciousness and consensus in Bangladesh.

During the war, Sadi's father was interrogated by the Pakistani military as they learned of his freedom fighter son, but he was eventually released after three days of torture.

Sadi's elder brother late Shegufta Bakht Chaudhuri was the chief controller of import-export, East and West Pakistan prior to the country's liberation.

Sadi's uncle (maternal) Dr. Syed Mujtaba Ali, a renowned Bengali scholar, author, academic and linguist, was one of his biggest inspirations.

Barely three and a half months after the Partition of India, Syed Mujtaba Ali was one of the first to call for Bangla as East Pakistan's state language on 30 November 1947, at the Sylhet Muslim Sahitya Sangsad.