Boothroyd was appointed Cobblers boss on November 29 last year and went on to successfully steer the club clear of relegation.
Town have made further improvements this season with a host of new faces and currently lie three points off the play-off places.
"Aidy does an awful lot of work behind the scenes that the fans don't necessarily see," Cardoza told the Northampton Chronicle.
"He's been a fantastic signing for us and he's turned us from a club that was in - not quite disarray - but looking at the Conference, to one that is upset that we didn't win on Saturday to go third or fourth.
"There was a real fear because we were only going one way. We knew Aidy would take some time to do well after replacing Gary Johnson and a couple of months into it we were still bottom of the league - but we've come a long way."