The move to the Sequoia Union High School District office in Redwood City will be more than a change of scenery.
"There are few jobs out there that are more demanding of your time than being a high school principal," Mr. Reilly said in an interview. "The job is a long-distance run but you have to sprint to keep up. ... It really is a 24/7 job. There's something going on every night of the week. The last five years have been probably the most challenging of my life."
In taking on the district post, he will succeed Susan Vickrey, who is retiring.
Asked about Mr. Reilly's successor at Woodside, district Superintendent James Lianides said that recruitment has begun and that he expects to name a new principal at the May 30 district board meeting. The position is open to candidates from inside and outside the district, he said.
Mr. Reilly's new responsibilities will include getting to know the cultures of the district's other three traditional high schools, including Menlo-Atherton. He said he plans to be a cross-pollinator of best teaching practices, but will spend his first year listening "to see how I can make the district an even better place to work."
The Sequoia district has been his workplace since 1995, when he came to Woodside High as a substitute teacher, joining the faculty in 1997. He left in 2005, when he was teaching journalism and advanced-placement English, to become administrative vice principal at Sequoia High School. He returned to Woodside as principal in 2007, when Linda Common moved on.
Mr. Reilly holds a bachelor's degree in English literature from the University of California, Los Angeles, a 1997 teaching credential from San Francisco State University, and administrative credentials.
His new role will also include labor negotiations, something he engaged in as a teacher but from labor's side of the table.
He said he receives three or four offers a year to work elsewhere. Why stay? The people he knows, his history with the district and his familiarity with the issues, he said. "I feel I can continue to effect change."
His legacy at Woodside High will be significant. Asked to describe it, Mr. Reilly noted a focus on "small learning communities," including special education and the Green Academy, and putting "the right teachers in the right classrooms." He also moved back the start of the first class of the day to 9 a.m. from 8 a.m. for most students. Research shows that students do better with more sleep.
The school also has at least one working garden. Such changes are "systemic (and) much ingrained," and will persist, he said.
Mr. Reilly introduced the initial steps for "flipping school," in which students view lectures on personal computers and save homework for the classroom. When fully implemented, students doing homework in class would reveal their understanding or lack of it in real time.
"This would level the playing field a little bit," Mr. Reilly said in March 2011, referring to advantages enjoyed by kids who do homework in homes with educated parents. "It's gathering momentum," he said when asked for an update.
Mr. Reilly used a parable to explain his leadership style. "When the good leader left, the people looked around and said, 'What do we do now?.' When the great leader left, the people said, 'We know what we have to do.' I strove to be the latter of the leaders."
"David has (had) some tough times here," said teacher Ann Akey, citing the film "Waiting for Superman." Using charter schools such as Summit Preparatory Charter High School in Redwood City as foils, the film accused the education establishment, including Woodside High, of failing to prepare students for a globally competitive world.
"He handled it well without becoming negative himself," Ms. Akey said.