Devendra's career in the public service started in 1953 as a District Land Officer. Later was General Manager of the River Valleys Development Project in Walawe.
Devendra served 40 years in the public service and was the Government Agent in Matara, Trincomalee and Jaffna. He also held positions as Chairman of the Public Service Commission, and Chairman of the Salaries Commission. First President of the Colombo University Alumni Association. Tissa also served as National Expert for the FAO and United Nations.
Devendra was an author and wrote a number of books, in both Sinhalese and English. His book Tales from the Provinces was short-listed for the Gratiaen Prize in 1998.[citation needed] Devendra was also a reviewer of English films along with the late Regi Siriwardena, Donald Abeysinghe, and Mervyn De Silva.
Devendra scripted a television documentary on George Keyt in 1987. His published books include:
The Emerald Island
Tales from the Provinces
Princes Peasants and Clever Beasts
More Princes, Peasants and Clever Beasts
On Horseshoe Street
Death
Tissa Devendra died on 22 June 2023, at the age of 94.[3]