Rudolf Schild-Comtesse was born in Zürich on October 12, 1900 and studied law there, in Bern, and in Heidelberg. After earning a Doctorate based on a thesis on labor law, Schild-Comtesse became a lawyer in Solothurn.
In 1925, Schild-Comtesse joined the family firm, Eterna (formerly called Schild Fréres), but this organization was in the midst of a crisis. In 1932, during the Great Depression, Eterna was forced to join ASUAG with other Swiss watch manufacturers. Because ASUAG had organized watch movement manufacturing under Ebauches SA, Eterna was split in two. Watchmaking remained under the Eterna name within ASUAG, but construction of watch movements was spun off into ETA SA Fabriques d'Ebauches.
Schild-Comtesse joined the board of directors at Ebauches SA in 1951, an officer of the company in 1956, and managing director in 1964. There, he directed not just Eterna's ETA movement operations but also those of cousin company A. Schild, FHF, and many others. He presided over the company as it developed advanced automatic movements, including Heinrich Stamm's Eterna 1466 and high-beat movements from ETA.
Apart from overseeing Ebauches SA, Schild-Comtesse also joined the board of General Watch Company within ASUAG. From this position, he oversaw the consolidation of the industry in the 1970s during the quartz crisis.
Schild-Comtesse also participated in many Cantonal and Federal commissions and was a member of the board of the Cantonal Bank of Solothurn. He also co-founded the hospital in Grenchen, home of Eterna.