A member of the Democratic Party, she has led the nation's financial sector through the economic crisis caused by the inflation surge and the Russian invasion of Ukraine.

After briefly living in Germany, the family returned to Japan, residing in the Tokyo area for eleven years.

The following year, she received a master's degree in European political and administrative studies from the College of Europe in Bruges.

[3][4] On 1 June 2020, Backes was appointed Luxembourg's first female Hofmarschall (French: Maréchale de la Cour, English: Marshal of the Court), the highest administrative position in the household of Grand Duke Henri.

[6] On 3 December 2021, the ruling coalition government announced that Backes would become the new Minister for Finances, succeeding Pierre Gramegna and becoming the first woman to hold the office.

[4] Though initially intending her tenure to operate ad interim with a "simple" economic framework, the Russian invasion of Ukraine, which began the month after she took office, exasperated Luxembourg's ongoing inflation crisis.

She also reiterated Luxembourg's support for Ukraine during a meeting with Ukrainian finance minister Serhiy Marchenko.

Among the topics of discussion were capital market cooperation, green finance, and Luxembourg's desire to strengthen diplomatic and economic ties with China.

[15][16] She also oversaw a 1% reduction in the value-added tax as part of an inflation-reduction measure,[17] as well as the implementation of international taxation on multinational corporations based in Luxembourg, which affected around 7,500 firms.