Hernández de Cos joined the Bank of Spain in 1997 as economist of its research service. Between 2004 and 2007 he was advisor to the executive board of the European Central Bank. From 2015 he held the position of general director of the Directorate General of Economy and Statistics of the organization after the resignation of Luis Malo de Molina who had held the position since 1992.[4]
The press has highlighted the technical nature of Hernández de Cos' profile, with no political past.[2][10][11] The Ministry of Economy, following the announcement of his appointment, stressed that "he is an excellent candidate for the post of governor due to his great technical training, particularly in banking and monetary matters; his political independence; and his experience and prestige in the Bank of Spain and the European Central Bank."[3]Unidos Podemos has described him as "a hawk, but with an impeccable technical profile and, at least, he knows economics."[3] Hernández de Cos himself has publicly advocated for giving the Parliament a greater role in the appointment of central bank chiefs and extending future governorship terms to eight years from six.[12] Hernández de Cos was the second youngest governor since Spain's transition to democracy after José Ramón Álvarez Rendueles, who was appointed governor in 1978, at the age of 38.
Hernández de Cos' six-year term ended on 11 June 2024, automatically leaving office and being replaced by the deputy governor, Margarita Delgado Tejero, until the appointment of a new incumbent.[15]
In 2024, he joined the faculty of IESE Business School as Professor of the Practice of Management.[1]