He went to the three-year HBS, where together with classmates Albert van Dalsum and Adolf Bouwmeester he founded the "HBS-Bond" in order to organize theatre productions.

In 1905, Ruys started his acting career at the Nederlandsche Tooneelvereeniging of Adriaan van der Horst; initially as a volunteer, but after only three months he got a permanent commitment.

Ruys and De Bree regularly performed together as a duo in pieces such as Vicki Baum's Grand Hotel, Marcel Pagnol's Monsieur Topaze and, most notably, Potash and Perlmutter.

[3] The two also starred together in the extremely popular feature film The Crosspatch by Henry Koster, which played in Dutch cinemas for no less than seven years and proved a commercial success in the United Kingdom as well.

There he played popular characters such as Flip Bangert, a man who is terribly afraid of his wife, and Piet Piederiet, a flutist without a palate, in often largely improvised skits.