After qualifying in 1919, Stam began working as a draftsman with an architectural firm in Rotterdam. He boldly stated between his qualification and first career that "We have to change the world." The architectural firm was run by the architect Granpré Molière. Molière was a traditionalist, and had a different style of design to Stam, but the two worked together well, possibly because they were both Christians, and Stam was invited to work for Molière personally in his studio in Rotterdam.