Aramayo was one of Bolivia's three principal tin magnates alongside Simón Iturri Patiño and Mauricio Hochschild in the early 20th century.

The holding company represented the assets of the Aramayo family in mining (mainly bismuth, tin, tungsten, and other metals) and land properties across Bolivia.

In 1935, Aramayo was appointed as Bolivia Finance minister by president José Luis Tejada Sorzano.

During his lifetime, Aramayo had different important positions in his country and abroad as newspaper owner (La Razon), Member of Congress, Ambassador of Bolivia to London and Paris, Minister of Finance and Minister of Foreign Affairs during president Sorzano's term.

After his death, he was succeeded as President of CAMB and MCP by his nephew John German-Ribon.