By Amy Eisen, News Correspondent

From 3-year-old mouths chomping on Duplos to 12-year-old hands building models of airplanes or space ships, many kids of the 90s and even later remember growing up with Legos. This past weekend, on Sunday, Jan. 26, the Legoland Discovery Center hosted its Master Builder Competition to play host to those childhood memories and inspire a new master builder.

Brick Factor, this past weekend’s competition held at the Boston Public Library, was not the average science fair. Contestants had to use their creativity and Lego architecture skills to create on-the-spot designs, while interacting with a crowd of excited children. The winner of the contest, Ian Coffey, received not only a one-time prize, but also a full-time, salaried position as master builder at the new Legoland Discovery Center, set to open in Somerville in May.

Over 100 contestants participated in the first round on Saturday, when they had 30 minutes to design their own Lego creations based on two themes: favorite book and favorite vacation spot. The top 10 then moved on to Sunday’s contest, where the contestants had 45 minutes to create designs that best reflected themselves.

According to Jeremiah Boehr, the current master builder at the Legoland Discovery Center in Kansas City, the position of master builder isn’t just about Lego construction prowess. It’s also about interacting with kids and enriching their experience at the center.

Boehr was one of the judges at the Brick Factor.

“You’re the face of the attraction,” he said.

Coffey, 26, said he is ready for his new position. He will have to leave his current job in politics in Albany, NY and move to Boston. Coffey never really knew what his dream job was until he won this unorthodox job interview contest, he said.

“Legos – full time? Hands down best job,” he said.

The judges said Coffey stood out for the way he involved his eager young fans, even letting them choose his color scheme. His final design was an easel displaying a portrait of him and his dog, accompanied by a palette with different colored paintbrushes.

“I’ve been playing with Legos ever since I was a kid,” Coffey said. “I’m still a kid at heart.”

The contestants were judged for how they interacted with the crowd, and also, of course, for their skill and creativity. So how do the contestants hone their Lego skills?

“You’ve got to build a lot,” master builder Boehr said. “And build your own creations, not just a set with instruction.”

Many of last weekend’s competitors didn’t have much time to play with legos. Most already had full-time jobs, including teaching and engineering. The master builder position does not require any formal background or training, and some of the contestants hadn’t played with Legos in years.

Finalist Ian Dulin said he didn’t even get a chance to practice before the big event. All of his Legos were still at his parents’ house, so he had to visualize his designs to practice.

“But it’s just like riding a bike,” Dulin said.

The job of master builder is not always all fun and games. When the center has an event, construction deadlines can keep the builder working all night. Of Boehr’s projects so far, his favorites include a 5-foot-wide pumpkin for a Halloween event, as well as a 5,000 brick replica of the Titanic, which was a two-month long project.

The new center in Somerville will be a 44,000 square foot indoor mini-land for all ages. It will be the first center in New England and will include rides, 3D films and a variety of interactive Lego games. Lego replicas of Boston landmarks will also be featured, as soon as Coffey begins working.

The large and enthusiastic crowd at the Brick Factor event added an additional challenge to the contestants, but also provided a positive atmosphere. And as Boehr said, “You can’t get into such a bad mood when you’re working with Legos.”