Nowhere are the winds of change clearer than in North Block, where officials are working longer hours and weekends, and with a new sense of urgency and accountability.
"His message is very clear. Either you have to perform or find a way to move out of the ministry," said one official, who attended Chidambaram's first meeting with senior staff.
Reinforcing the message of change was the appointment of Raghuram Rajan (seen here), the outspoken former chief economist to the International Monetary Fund, as Chidambaram's top adviser.
Earlier this year, Rajan offered a stinging critique of the government's economic policies at an event attended by Singh.
Since Chidambaram's arrival, senior ministry officials have been logging their arrival and departure each day using fingerprint scanners located at the building's entrances.
Earlier, only junior staff were required to do so.
"What he has done is put everyone on their toes and made them accountable," the official said.