KARACHI, Pakistan — Since Pakistan’s biggest electricity company was privatized, its headquarters has been looted, its employees kidnapped and its boss nearly arrested by the government.

Despite all of that, it is regarded as a roaring success.

Power cuts lasting 12 hours a day or more have devastated the Pakistani economy. The loss of millions of jobs has fueled unrest in a nuclear-armed nation already beset by a Taliban insurgency.

The only city bucking the trend is the violent metropolis of Karachi, Pakistan’s financial heart — and that is thanks to Tabish Gauhar and his team at the Karachi Electricity Supply Co.

“It has consumed every ounce of my energy,” Mr. Gauhar, 42, said in an interview. “But we have helped millions of people.”