A former Google executive who headed "personalization" for the search giant, Ventilla said the light-bulb moment came when he started researching private schools in San Francisco for his preschool-age daughter.
"We weren't seeing the kind of experiences that we thought would really prepare her for a lifetime of change," he said.
"The goalpost has moved. It's become much more difficult to do your job as an educator and actually prepare students for the 2030s, '40s and '50s."
The end result: a $133 million school startup known as AltSchool. Facebook CEO Mark Zuckerberg and his wife, Priscilla Chan, have made education a centerpiece of their philanthropy. They are among the venture's high-profile investors.
Looking for a new challenge, Ventilla pondered how one might rethink the entire school experience and apply personalization to a pre-K through eighth-grade school. In essence, he's applying what he learned in Silicon Valley and merging that with education.
Technology firms have made an art of serving up specialized content based on your preferences. Ever wondered how Netflix always knows what to recommend? AltSchool's teams of 50 engineers do sort of the same for students.
The school uses custom software to personalize education for each child. Teachers work with students around that customized curriculum. While AltSchool is a for-profit venture that's building (and investing) heavily in its own brick-and-mortar schools, its long-term business plan is to license out the technology to other schools in the future, including to public schools.
"We have more engineers than any elementary school system on the planet," said Ventilla, who attended the prestigious Phillips Academy in Andover, Massachusetts, for high school, then Yale University, where he earned a degree in mathematics and physics.
"We build a dashboard for educators called learning progression where each teacher can kind of see for every child in that classroom, what's the frontier of learning for that kid? Where are they struggling? Where are they ahead? That kind of technology gives educators the information to make good decisions that no amount of pen and paper and dedication could provide."
Students are served up a "play list," where each has a list of 25 items they are responsible for each week. Peering into a student's Google Chromebook, the list reveals a series of activities, called cards, that might vary from using an iPad learning app to watching an instructional video.
The idea is that the teacher uploads cards designed to help that student learn and thrive. But an underlying concept is that students are given autonomy over what they want to work on and when, a learning approach that sounds similar to Montessori schools. In fact, when the first AltSchool opened three years ago in San Francisco, it was quickly dubbed "Montessori 2.0."
AltSchool also differs from traditional schools in that it has mixed-aged classes, though none are more than a couple years apart in any classroom. Its program is pre-K through eighth grade. Ventilla said it doesn't make sense to him that children would be limited by age specific content.
"It's saying, 'This is the bucket you fill up and if you get to the end of the material, well you have to wait until next year,'" he said. "That's crazy."
Inside one of its so-called "micro schools," it's striking how many video cameras are affixed to the walls. The reason is that school days are recorded, allowing teachers to review the footage to determine a student's engagement level or progress. It might also be a deterrent to bad behavior.
Next fall, AltSchool will have approximately 400 students spread across nine locations in San Francisco, Palo Alto and New York. Chicago and another New York location are expected to open in 2017.
The concept has apparently proven popular, even with tuition at a cost of about $25,000 per year -- actually less expensive than many private schools in the Bay Area. Ventilla said demand has outstripped the spots that it can offer, with an acceptance rate at less than 10% across its schools.
The demand for teacher jobs seems to be high, as well. Nearly 3,000 people applied last year for only 24 jobs. Part of the draw is that teachers get equity or stock options, just like many employees at Silicon Valley firms.
"If (teachers) do well and AltSchool does well, there could be a transformative financial outcome where they could buy a house or have the freedom not to work, " said Ventilla.
Christie Seyfert, a middle school teacher, said it has been liberating in multiple ways.
"At AltSchool, I have autonomy to teach whatever I want, however I want to teach it -- as long as it is in collaboration with other teachers and in the spirit of providing an amazing education, " she said.
In the short term, the school seems to be receiving high marks from its early adopters.
Nancy Bernstein said her fourth-grade daughter was struggling in her previous private school and becoming discouraged.
"She's never used the word 'passion' before until she came to AltSchool. Here the difference is they are teaching them, but they're igniting the kids to figure out what they're interested in."
AltSchool, however, has its critics. They say while its goals are admirable, it's hardly improving education for the masses.
"Ultimately, it comes down to this particular school catering to a particular group of people, said Larry Cuban, a professor emeritus of education at Stanford University and historian of school reform.
"There have been many previous efforts to start schools in the private sector to move public schools into something approximating what these reformers want. In every single case that I can recall, it did not happen. "
Ventilla, however, is undaunted and believes his model of personalization and choice will spread over time.
"People tend to like things better when they have some choice, rather than when they're told exactly what they need to do -- when and how," he said.
Next year, Ventilla's inspiration for launching a school will come full circle. His daughter will be a first-year student at AltSchool.