[1] He served as the Dean of the Faculty of Mechanical Engineering and as the Vice-Rector for Science at Gdańsk University of Technology.
[2] After graduating, he took an apprenticeship as a ship's mechanic's assistant North-Atlantic line of the Danish Shipbuilding Company "Det Ostasiatyske Co".
[3] A year later, Mieczysław was admitted to the School of Mechanical Engineering of the Warsaw University of Technology,[2] but he interrupted his studies in 1928 to return to merchant ships, this time in the French shipbuilding company "Chargeurs Rennis".
From 1934 until the outbreak of World War II, he worked as a designer at the Study Office of the State Engineering Institute in Warsaw on several projects, including the PZInż 703.
[3] During the war, he was involved in small-scale trade and production, and was also a member of the Kedyw, where he was responsible for automotive matters such as transporting supplies and ammunition, as well as providing driving lessons.