For the past couple of years he has been director of the Lambeth education action zone in south London. He was brought in to deal with management problems after the zone was set up.
His first experience of dealing directly with the Department for Education and Employment was at the Qualifications and Curriculum Authority. During his three years there, Mr Coulson moved from the assessment division to became principal manager for school improvement. His main task was to draft guidance for schools.
Much of his earlier career was spent in junior schools, though he did spend a year as an inspector and adviser in the north-east London borough of Waltham Forest. For five years in the early Nineties he was headof William Tyndale primary in Islington - a period during which the once-controversial school's reputation improved.
Mr Coulson, 41, takes over the running of the Government's numeracy drive in primaries from Anita Straker after Easter. Ms Straker has moved on to become director of the Government's latest key priority - to improve standards in the first three secondary years.
So far, the numeracy strategy appears to have had a remarkable impact on schools. Last year, almost three-quarters of all 11-year-olds achieved the required level in maths, compared with only 44 per cent in 1995.
It will be the job of Mr Coulson to ratchet up standards further so that the Government hits its 2004 targets.
Ministers want 85 per cent of children leaving primary school to have achieved level 4 - an increase of 13 percentage points - and 35 per cent to have reached level 5 - an increase of 11 percentage points.