Sam Chaudhary
Cofounder and CEO of ClassDojo
Where to hear and read about Sam Chaudhary1 episode or test
Sam Chaudhary is cofounder and CEO of ClassDojo, which grew teacher by teacher into use in about 95% of US K-8 schools with no paid acquisition. The most useful thing to learn from him is to build a trusted network first, tie incentives to end users, and monetize late with optional extras that never gate learning.
we should live or die based on our ability to serve kids and families
How ClassDojo Built Network Effects to Reach 95% of US K-8 Schools
Sam Chaudhary: the story and the lessons
1Sam Chaudhary's path from teaching to ClassDojo
Teaching as a child pulled Chaudhary from economics toward education. He taught as a pupil and later at a school in the Middle East, where kids spent about a third of their time teaching as well as learning. He was heading for a PhD before this.
He then joined McKinsey's education team, which let him question ministers from top-performing school systems. A Cambridge professor also sent him to help a friend's school teach economics and maths better.
He met cofounder Liam Don at a weekend hack event. They met at a UK hack event building an unrelated Mac app. Liam was a game developer at Jagex, maker of RuneScape, and was doing a computer science PhD on technology that helps kids learn.
Liam's games background later shaped Dojo Islands.
They picked education over energy as the problem worth a career. They narrowed the biggest problems to energy and education. Enough energy covers survival, while education lets people find their talents, which is how the future beats the past.
They saw that most edtech sold to schools, so nobody served teachers, kids and parents well. They joined the first cohort of an education incubator tied to Y Combinator, with a trivial classroom seating chart app as their application demo and no exact entry point yet.
His mission traces back to his father's path out of a Pakistani village. His father worked hard at school, had a few great teachers and became a doctor in the UK.
Chaudhary asks, "wouldn't it be cool if you could give every kid on the planet a chance to make the most of what they've got?"
2Why Chaudhary built for families instead of selling to districts
He tied the company's incentives to kids and families, not budgets. Chaudhary saw that B2B edtech chases budget, then the richest districts, and skips the kids who need it most. ClassDojo chose to be a consumer company so it would live or die on whether families benefit.
He cites Charlie Munger: show me the incentive and I'll show you the outcome. School software gets sold and sits for years, so survival never depends on users. Duolingo was the only other company he saw thinking this way.
Teachers were the way in because families trust them. Reid Hoffman told the founders that every great consumer company needs a network for growth. Teachers were the trusted people who could reach parents and kids.
Outsiders new to the US, the founders were discouraged at first by the edtech founders they met. They held that every family wants a better education, so one company should be able to serve them all.
He spoke to 400 to 500 teachers before choosing a product. In the first month or two he emailed lists, went to meetups and taught summer school in Palo Alto, trading teaching for feedback.
He now calls the email outreach "spamming", with apologies. The top problem to emerge, managing 30 kids, was unglamorous and non-obvious.
The first product made classroom management positive instead of punitive. Teachers picked values such as being kind or asking a good question, and kids got a digital plus one for each. It reached about 12,000 teachers by demo day, around half a percent of US teachers, with no paid acquisition.
Teachers mostly had detention and punishment, applied after something went wrong. Classroom management is a major cause of teacher burnout and a barrier to learning.
3How ClassDojo found product market fit and spread school by school
Chaudhary called the early viral growth a false start. Word-of-mouth signups felt like fit, but cohort data a few months in showed teachers using the tool for a while and then leaving. Far from 90% of a cohort was active three months later.
"I'd say that was a false start." He counts the retention analysis among the most important the company has done.
He cut cohorts by who stayed and copied their behavior. A subgroup stayed as active on day 90 as on day 7. Phone calls showed they were all hacking their own way to reach parents, by screenshotting the site into emails or printing reports.
That led to parent and kid accounts with shared photos, videos and messages.
Turning a single-player tool into a multiplayer one fixed retention. Once parents and kids were in, both sides found it harder to drop off. Real product market fit followed, with viral growth and retention.
Parents wanted it too, since a parent-teacher conference might come only once a semester.
He tracks early connection with families as the retention signal. Teachers who connect with kids and families early show fantastic retention and engagement. Chaudhary compares it to Facebook's seven friends in 10 days.
Inside a school, Dojo starts with one teacher, lights up the school, then jumps to the next. It is now used in about nine of 10 US schools.
He found emergent spreading behavior and made it easier. Every school had an early-adopter teacher already telling colleagues. ClassDojo gave them a ready-made presentation with a QR code at the end so colleagues could join the school.
"you look for emergent behavior." The fix was low tech but supported the land-and-expand pattern.
A teacher intern's analysis led to the mentor community. Jenna, a fifth-grade science teacher in San Francisco, interned when the company had six or seven people. Her summer analysis of how Dojo grows led her to stand up a community of passionate early-adopter teachers.
These teachers are often isolated in their schools, and the community became a source of advice, feedback and encouragement. "You can't hack it. You kind of have to just put in years of care and conversations and relationship building."
He treats network effects as one route to lasting defensibility. Hamilton Helmer's book 7 Powers became a bit of a bible for how the company thinks about defensibility. Chaudhary had Helmer lecture the leadership team.
The aim is an enduring business, not a flash in the pan. The other powers Helmer names include scale economies, brands and switching costs.
4How Chaudhary monetized without breaking teachers' trust
He built the network first and took no revenue for years. Six years in, ClassDojo had zero revenue and about 25 people. They took Hoffman's advice to prioritize a network, betting it would open many ways to monetize later.
"if we never build a network then you know we're just going to run out of growth channels." The year of monetization came only once growth looked repeatable.
Plus charges for convenience and never blocks learning. The first extras were optional, such as Memories, which turns a year of a child's photos into a yearbook-style album. About 5% of the base pays for something on Dojo.
Paying families fund free access for everyone else. The price stays under $100 a year and the company chose not to run ads.
He warned teachers before launching paid features. The team told teachers ahead of time that ClassDojo stays free forever for kids and families and that optional paid extras were coming. Trust held after monetization began about six to seven years in.
Chaudhary says most companies just do things to you, and the aim was to build it with teachers: "can we build this with you?"
He wants Plus to become a Prime for education. Most of the world cannot spend $50,000 on private school, but many families could spend about $100 a year.
He cites Bezos's idea that Prime should be so valuable it would be irresponsible not to buy it, and wants the same test passed by Plus.
5The new businesses Chaudhary launched on the Dojo network
One rule governs every new business: the long-term best interest of kids. Chaudhary says this is the single principle in the company's mission, strategy and modes document, which everyone reads on joining. It rules out products that just steal kids' attention.
Hundreds of family interviews a week show which needs to serve next.
Tutor uses the network to avoid acquisition costs on both sides. It matches families already on Dojo with teachers already on Dojo, so families pay less and teachers earn more. Three in four paying families had never paid for a tutor before.
The team rebuilt a small YC tutoring company from South America on Dojo after its founders joined. Dojo underwrites the quality of visits. It began with US math and reading for K through 5, and group classes of up to six or seven kids launched last quarter.
Dojo Islands builds a safe kids space from the trust graph. Dojo already holds each child's trusted adults and friends, so each group of kids gets its own Minecraft-like island and discovers games made by other kids, with no strangers.
The idea came from pandemic-era parent worries about screens and unsafe online games. The founders drew on Liam's Jagex experience and met the founder of Club Penguin and early Roblox team members.
Dojo Sparks applies AI to reading and caps screen time. Sparks turns the science of reading into an adaptive game that listens to the child and speaks back. Sessions are capped at about 15 minutes. Early results show kids moving two grade levels in about four to five months.
The CTO first built it for his own kids, and it is one of Dojo's fastest growing products. Chaudhary points to 2024 NAEP scores, where about seven in 10 ten-year-olds in the US are not proficient. The results are early and shown without a study.
He wants AI to scale tutoring while keeping struggle in learning. He cites Bloom's two sigma finding, which says one-on-one tutoring lifts a kid from the 50th to the 98th percentile, and says AI can finally scale it.
Citing Niall Ferguson's starship and cloister, he says kids need both full access to the latest tools and hard problems faced alone. By 2030 he wants Dojo to reach every kid on the planet.
6How Chaudhary runs the company and what he would change
He runs a small, hand-selected team against a huge user base. About 200 people serve 50 million kids, all hand selected.
He wants to reward errors of initiative, not errors of inaction. Chaudhary says growing companies drift toward rewarding people who do nothing, since they can't be blamed for mistakes. He wants to keep recognizing mistakes that come from boldness.
"what you want to uh recognize and reward is like errors that come from taking initiative and from boldness."
He says international expansion should have been deliberate. ClassDojo did not go international on purpose and was "yanked into it", which made for a rough early stretch. He says the company does it well now.
He would have expanded in a more concerted and rigorous way.
His one superficial regret is not affording dojo.com early. The company could not afford the domain in its early years.
How ClassDojo Built Network Effects to Reach 95% of US K-8 Schools
ClassDojo grew teacher by teacher with no paid acquisition, built a three-sided network of teachers, parents and kids, and then monetized with optional extras without breaking trust. The result is use in about 95% of US K-8 schools, about 5% of the base paying, and new businesses (Tutor, Islands, Sparks) launched on top of the network.
Teaching as a child pulled Chaudhary from economics toward education. He taught as a pupil and later at a school in the Middle East, where kids spent about a third of their time teaching as well as learning. He was heading for a PhD before this.
He then joined McKinsey's education team, which let him question ministers from top-performing school systems. A Cambridge professor also sent him to help a friend's school teach economics and maths better.
He met cofounder Liam Don at a weekend hack event. They met at a UK hack event building an unrelated Mac app. Liam was a game developer at Jagex, maker of RuneScape, and was doing a computer science PhD on technology that helps kids learn.
Liam's games background later shaped Dojo Islands.
They picked education over energy as the problem worth a career. They narrowed the biggest problems to energy and education. Enough energy covers survival, while education lets people find their talents, which is how the future beats the past.
They saw that most edtech sold to schools, so nobody served teachers, kids and parents well. They joined the first cohort of an education incubator tied to Y Combinator, with a trivial classroom seating chart app as their application demo and no exact entry point yet.
His mission traces back to his father's path out of a Pakistani village. His father worked hard at school, had a few great teachers and became a doctor in the UK.
Chaudhary asks, "wouldn't it be cool if you could give every kid on the planet a chance to make the most of what they've got?"
He tied the company's incentives to kids and families, not budgets. Chaudhary saw that B2B edtech chases budget, then the richest districts, and skips the kids who need it most. ClassDojo chose to be a consumer company so it would live or die on whether families benefit.
He cites Charlie Munger: show me the incentive and I'll show you the outcome. School software gets sold and sits for years, so survival never depends on users. Duolingo was the only other company he saw thinking this way.
Teachers were the way in because families trust them. Reid Hoffman told the founders that every great consumer company needs a network for growth. Teachers were the trusted people who could reach parents and kids.
Outsiders new to the US, the founders were discouraged at first by the edtech founders they met. They held that every family wants a better education, so one company should be able to serve them all.
He spoke to 400 to 500 teachers before choosing a product. In the first month or two he emailed lists, went to meetups and taught summer school in Palo Alto, trading teaching for feedback.
He now calls the email outreach "spamming", with apologies. The top problem to emerge, managing 30 kids, was unglamorous and non-obvious.
The first product made classroom management positive instead of punitive. Teachers picked values such as being kind or asking a good question, and kids got a digital plus one for each. It reached about 12,000 teachers by demo day, around half a percent of US teachers, with no paid acquisition.
Teachers mostly had detention and punishment, applied after something went wrong. Classroom management is a major cause of teacher burnout and a barrier to learning.
Chaudhary called the early viral growth a false start. Word-of-mouth signups felt like fit, but cohort data a few months in showed teachers using the tool for a while and then leaving. Far from 90% of a cohort was active three months later.
"I'd say that was a false start." He counts the retention analysis among the most important the company has done.
He cut cohorts by who stayed and copied their behavior. A subgroup stayed as active on day 90 as on day 7. Phone calls showed they were all hacking their own way to reach parents, by screenshotting the site into emails or printing reports.
That led to parent and kid accounts with shared photos, videos and messages.
Turning a single-player tool into a multiplayer one fixed retention. Once parents and kids were in, both sides found it harder to drop off. Real product market fit followed, with viral growth and retention.
Parents wanted it too, since a parent-teacher conference might come only once a semester.
He tracks early connection with families as the retention signal. Teachers who connect with kids and families early show fantastic retention and engagement. Chaudhary compares it to Facebook's seven friends in 10 days.
Inside a school, Dojo starts with one teacher, lights up the school, then jumps to the next. It is now used in about nine of 10 US schools.
He found emergent spreading behavior and made it easier. Every school had an early-adopter teacher already telling colleagues. ClassDojo gave them a ready-made presentation with a QR code at the end so colleagues could join the school.
"you look for emergent behavior." The fix was low tech but supported the land-and-expand pattern.
A teacher intern's analysis led to the mentor community. Jenna, a fifth-grade science teacher in San Francisco, interned when the company had six or seven people. Her summer analysis of how Dojo grows led her to stand up a community of passionate early-adopter teachers.
These teachers are often isolated in their schools, and the community became a source of advice, feedback and encouragement. "You can't hack it. You kind of have to just put in years of care and conversations and relationship building."
He treats network effects as one route to lasting defensibility. Hamilton Helmer's book 7 Powers became a bit of a bible for how the company thinks about defensibility. Chaudhary had Helmer lecture the leadership team.
The aim is an enduring business, not a flash in the pan. The other powers Helmer names include scale economies, brands and switching costs.
He built the network first and took no revenue for years. Six years in, ClassDojo had zero revenue and about 25 people. They took Hoffman's advice to prioritize a network, betting it would open many ways to monetize later.
"if we never build a network then you know we're just going to run out of growth channels." The year of monetization came only once growth looked repeatable.
Plus charges for convenience and never blocks learning. The first extras were optional, such as Memories, which turns a year of a child's photos into a yearbook-style album. About 5% of the base pays for something on Dojo.
Paying families fund free access for everyone else. The price stays under $100 a year and the company chose not to run ads.
He warned teachers before launching paid features. The team told teachers ahead of time that ClassDojo stays free forever for kids and families and that optional paid extras were coming. Trust held after monetization began about six to seven years in.
Chaudhary says most companies just do things to you, and the aim was to build it with teachers: "can we build this with you?"
He wants Plus to become a Prime for education. Most of the world cannot spend $50,000 on private school, but many families could spend about $100 a year.
He cites Bezos's idea that Prime should be so valuable it would be irresponsible not to buy it, and wants the same test passed by Plus.
One rule governs every new business: the long-term best interest of kids. Chaudhary says this is the single principle in the company's mission, strategy and modes document, which everyone reads on joining. It rules out products that just steal kids' attention.
Hundreds of family interviews a week show which needs to serve next.
Tutor uses the network to avoid acquisition costs on both sides. It matches families already on Dojo with teachers already on Dojo, so families pay less and teachers earn more. Three in four paying families had never paid for a tutor before.
The team rebuilt a small YC tutoring company from South America on Dojo after its founders joined. Dojo underwrites the quality of visits. It began with US math and reading for K through 5, and group classes of up to six or seven kids launched last quarter.
Dojo Islands builds a safe kids space from the trust graph. Dojo already holds each child's trusted adults and friends, so each group of kids gets its own Minecraft-like island and discovers games made by other kids, with no strangers.
The idea came from pandemic-era parent worries about screens and unsafe online games. The founders drew on Liam's Jagex experience and met the founder of Club Penguin and early Roblox team members.
Dojo Sparks applies AI to reading and caps screen time. Sparks turns the science of reading into an adaptive game that listens to the child and speaks back. Sessions are capped at about 15 minutes. Early results show kids moving two grade levels in about four to five months.
The CTO first built it for his own kids, and it is one of Dojo's fastest growing products. Chaudhary points to 2024 NAEP scores, where about seven in 10 ten-year-olds in the US are not proficient. The results are early and shown without a study.
He wants AI to scale tutoring while keeping struggle in learning. He cites Bloom's two sigma finding, which says one-on-one tutoring lifts a kid from the 50th to the 98th percentile, and says AI can finally scale it.
Citing Niall Ferguson's starship and cloister, he says kids need both full access to the latest tools and hard problems faced alone. By 2030 he wants Dojo to reach every kid on the planet.
He runs a small, hand-selected team against a huge user base. About 200 people serve 50 million kids, all hand selected.
He wants to reward errors of initiative, not errors of inaction. Chaudhary says growing companies drift toward rewarding people who do nothing, since they can't be blamed for mistakes. He wants to keep recognizing mistakes that come from boldness.
"what you want to uh recognize and reward is like errors that come from taking initiative and from boldness."
He says international expansion should have been deliberate. ClassDojo did not go international on purpose and was "yanked into it", which made for a rough early stretch. He says the company does it well now.
He would have expanded in a more concerted and rigorous way.
His one superficial regret is not affording dojo.com early. The company could not afford the domain in its early years.