Despite sometimes tough questioning - one resident told him he would be "walking into a dysfunctional system" - Martinez appeared unruffled by the prospect of coming to a district that is nearly insolvent and on the brink of a complete overhaul.
"I'm not afraid of a $300 million deficit," he said at one community session.
Martinez is a certified public accountant who worked as chief financial officer in Chicago, the nation's third-largest school system, and deputy superintendent in Nevada's Washoe County, which includes Reno. He's also a finalist for that district's top job now.
While working in Chicago under Arne Duncan, now U.S. education secretary, they searched for the single thing that was going to fix the tough system, Martinez said.
They found there was no such formula. The keys, he said, always are "a good principal, teachers feeling supported, and a great learning environment."
Martinez repeatedly stressed his experience and how it would help him in Philadelphia - how he helped raise the graduation rate in Reno and Las Vegas, how he overcame big deficits to build up financial reserves in Chicago. He talked about creating academic plans for every student and making schools safer.
A trim 42-year-old in a dark suit and yellow tie, Martinez was on his A-game in meetings - asking questions, nodding at speakers' statements, shaking hands, joking about his inability to pass up pizza, talking about his family.
Martinez was born in poverty in Mexico, the oldest of 10 children, four of whom are now teachers.
His parents, who had second-grade educations, brought the family to Chicago when Martinez was 5. He was the first in his family to graduate from high school and college, and his background propels him, he said.
"There's nothing that motivates me more than that. I know what it means to not have anything," said Martinez, who is married with a young son he said he would send to Philadelphia public schools.
Asked what he thought about the district's controversial blueprint for transformation, which has proposed closing 64 schools and grouping the rest of them into "achievement networks" run either by the district or by outside organizations, like universities or charters, Martinez said he thought there was "a vacuum of details."
But he said change was necessary.
"So many times in our world, K-12, we do the same things over and over again because that's the way we've always done it," Martinez said. "I think this is a chance to reimagine the system."
He said the district needed to focus on two things in the forthcoming overhaul and always: Do neighborhoods have good schools? How do we harness talent?
"I'm very comfortable using charters as one of our tools," he said. "In some communities, frankly, sometimes charters can be the best solution. In other communities, we can transform the schools that are there."
Martinez is a product of the Broad Superintendents Academy, which trains educational leaders to run urban districts and incorporate some business practices into education.
When Philadelphia teachers asked what that would mean, Martinez acknowledged that Broad superintendents have a reputation for ripping up existing structures to put their own in place.
That's not him, Martinez said. "I believe it really is about building on what we have now," he said.
Throughout his marathon public job interview, Martinez spoke mostly in generalities, but some specifics emerged.
He said charters and district schools need to be held to the same standards. He thought the best teachers should be teaching the neediest students. He said he thought many top schools were too small. He said that he believes in investing in early childhood education, and that "competition is healthy" in the realm of schools. He said the central office needs to set the overarching vision, but schools must be able to make their own decisions.
In a lunchtime conversation with students, Martinez asked about school safety. Mastbaum High student Ryan Sharp said he thought schools needed more structure.
Martinez nodded. Things got better in Las Vegas because of consistent rules, he said.
"We had to change some of the adults," Martinez said. "It was really tough."
Later, when asked about how he'd shaken up schools, Martinez said that in the past, virtually all Las Vegas principals had gotten excellent ratings and only one had been fired. On his watch, there has been a lot of change, Martinez said, with most principals rated "average" and with ineffective principals pushed out, fired, or demoted.
Is he ready for the rough-and-tumble world of Philadelphia schools?
Absolutely, Martinez said.
"It's very hard for a superintendent to come into a community where people have apathy. I can do something with passion," he said.
The second superintendent finalist, William R. Hite Jr. of Prince Georges County, Md., will be in town Tuesday.
School Reform Commissioner Wendell Pritchett, who heads the superintendent search committee, said that while the SRC will consider the feedback of community members, it alone will make the final choice.
Pritchett said that decision could come as early as the end of this week.
Contact Kristen Graham at 215-854-5146, firstname.lastname@example.org, or on Twitter @newskag. Read her blog, "Philly School Files," at www.philly.com/schoolfiles.