Answer by taking a quote from the following article:

Kudlow was born and raised in New Jersey, the son of Ruth (nee Grodnick) and Irving Howard Kudlow. His family is Jewish. Kudlow attended the private Elisabeth Morrow School in Englewood, New Jersey until 6th grade. He then attended the private Dwight-Englewood School from the second half of middle school to high school.

In 1970, while he was still a Democrat, Kudlow joined Joseph Duffey's "New Politics" senatorial campaign in Connecticut. Duffey was a leading anti-war politician during the Vietnam war era. Kudlow, working with Yale University law student Bill Clinton as well as many other rising young Democratic students, was known as a "brilliant" district coordinator. Kudlow worked on the U.S. Senate campaign of Joseph Duffey, along with Bill Clinton, John Podesta, and Michael Medved, another future conservative, and in 1976, he worked on the U.S. Senate campaign of Daniel Patrick Moynihan, along with Tim Russert, against Conservative Party incumbent James L. Buckley, brother of William F. Buckley, Jr.  Kudlow began his career as a staff economist at the Federal Reserve Bank of New York, taking a position "as a junior economist in a job where a master's degree wasn't required." He worked in the division of the Fed that handled open market operations.  During the first term of the Reagan administration (1981-1985), Kudlow was associate director for economics and planning in the Office of Management and Budget (OMB), a part of the Executive Office of the President. While he worked at the OMB, Kudlow was also an advisory committee member of the Federal Home Loan Mortgage Corporation, more commonly known as Freddie Mac. In April 2005, New York Governor George Pataki included Kudlow in a six-member state tax commission.  Kudlow's name was floated by Republicans as a potential Senate candidate in either Connecticut or New York in 2016. In October 2015, U.S. Senator Richard Blumenthal, in an email to supporters, attacked Kudlow as "a champion of big corporations and big money" despite Kudlow's not announcing a run. In early December 2015, Jack Fowler of National Review created a 527 organization that encouraged Kudlow to run.

What did he do while he was working
He worked in the division of the Fed that handled open market operations.