Rabbi David Meyer cannot remember his first day at Hasmonean, but then, can you blame him? He was only two-and-a-half years old.

These days, the educator's memory bank is filled with Hasmonean moments; unsurprising since, over the past 40 years, he has held every post at the Barnet school - from student to teacher, and finally, executive head.

An impressive feat for someone who, when studying for his PGCE, wrote on his placement form he would like to go "anywhere but Hasmonean".

"I think the office administrator just saw the word and that was it," he says. "The sum total of my achievement in life is that, not only did I stay at the school for all those years, but I also now live one door away from the house I grew up in."

Despite Rabbi Meyer's long-term commitment to the school, 2015 has heralded new beginnings. In January, aged 48, he finally waved goodbye to his alma mater, and has now taken up a new post as executive director of the education agency, Partnerships for Jewish Schools (PaJeS).

I decided I'd rather build children than buildings

Education remains his top priority. "Leaving Hasmonean was difficult," he says. "It was hard to say goodbye, but I would rather have left when people wanted me to stay, rather than stay to a point they wanted me to leave.

"I am leaving behind very strong leadership but a new challenge is something that I have been dreaming of for many years."

For Rabbi Meyer, teaching has been his driving passion since that "lightbulb moment" in his early 20s when he dropped his studies in civil engineering and opted instead to do a postgrad in Jewish education.

"I decided I'd rather build children than buildings," he explains. "Even though the foundations are more challenging - certainly less stable."

He remembers that, when he first started teaching in 1992, Jewish education had a different face.

"Immanuel College had just opened. King Solomon didn't exist, JCoSS didn't exist," he says. "To be frank, none of us were doing a great job. I think the transformation in the quality of Jewish education over the past few decades, and especially over the past 10 years, is exceptional.

"One of the greatest challenges I have had, and continue to have, is communicating to parents that the experiences they had as children are considerably different to those their children will have - in a very positive way."

Informal education, for example, is an area he feels is unmatched in secular schools. "I actually founded the informal education department at Hasmonean, which at the time was quite exciting and cutting edge," he says. "We really tried to intertwine formal and informal studying - things like running Shabbaton programmes, or maztzah baking at Pesach."

"I think Jewish headteachers face a double challenge," he adds. "They not only have to manage the secular studies in the curriculum, but also the Jewish elements within the school.

"But that is also why our schools are so good - the pupils have a real sense of purpose and direction."

So what does he make of the current scrutiny faced by faith schools? Do they get a bad press? "There is without doubt a significant problem in regard to the attitude that the wider community has to faith schools," he says.

For him, such schools must exist - in the very least, to prevent extremist teachings taking place in unsupervised surroundings.

"The issue with the Trojan Horse scandal is that it had nothing to do with faith schools," he says. "In fact, it couldn't have happened within a faith school. They were actually taking over mainstream institutions that didn't have Section 48 inspections.

"Had they had specific inspections for the religious aspects of the school, they would not have been able to teach those fundamentalist attitudes.

"There is no greater danger of fundamentalism taking place than by turning around and removing the faith school education, and so allowing it to seep into mainstream schools and fester in an unmonitored fashion."

Rabbi Meyer is emphatic that faith schools do not alienate pupils; in his view, parents should be able to teach their children in any way they choose.

"You should never be frightened of education," he says. "That is not the enemy; the real enemy is ignorance."

Looking back at his teaching career, exam marks have only ever been half the story. "I think that results are one of the facets of a good education, but it is more than that: it is about looking at the tools we are giving our children so that they will become constructive members of our society.

"We have to be able to hand down our traditions and beliefs - that is an enormous responsibility, and not one that Ofsted necessarily picks up on."

He adds: "I often say that the true measure of a school is looking at alumni at the age of 30: what are they doing? Are they valued by society? Are they active members of the community?"

It is fitting, then, that the students who piloted his Beis Hamedrash programme - an after-school scheme designed to prepare pupils for yeshivah - are now at that later stage in life.

"I established the programme for sixth form. At the time, most of our boys were going off to yeshiva, but there was no real preparation beforehand; this allowed them to daven shacharit in the morning," he recalls.

"I initially faced an enormous amount of resistance; even people who supported me said: 'If this fails, you're out of a job.' In the first year, we had 35 boys sign up and in the second year, close to 100. Today, we have over 200 taking part and Pikuach (the Board of Deputies' inspection service) describes it as a jewel in the school's crown.

"It is wonderful to see the graduates of that first programme now with families, employed and actively involved in the community. There is nothing more I could ask for."

As for new challenges, he is keen in his new role at PaJeS to help foster links between Jewish schools and support them in broadening their networks. Sharing resources, he says, offers the possibility for real innovation.

"I actually wrote my MBA on the idea of centralising services for the community's schools, so my new job is an opportunity to develop the existing framework and take it to a new level," he says.

"Within the network, there will be clusters of schools that will work together to develop curriculum, strategise and create economies of scale."

He will miss teaching, but relishes the opportunity to improve education on a broader scale from the top down.

"When I started working my way up the ladder, I expressed my concern to my rabbi that the more I took on, the less I would be teaching inside a classroom," he remembers.

"My rabbi told me: 'If you teach one class, you have an impact on 30 people; but if you lead a school, you have an impact on every single pupil. That was a guiding principle for me."

"I never wanted to be an administrator," he adds. "I always wanted to be an educator."