Wozzii
Ed-tech startup I co-founded · 2019 to 2021
A collaborative classroom built on top of YouTube, where scattered tutorials become courses and the notes one learner writes stay there for the next. I co-founded it and was its lead programmer.
- The problem
- YouTube tutorials need structure and shared notes to work as courses.
- What I did
- I co-founded it and led a three-person team, owning the data model, payments and reviews.
- The result
- A collaborative classroom where users learn as a community.
Turning YouTube tutorials into a place to learn together
YouTube has plenty of useful tutorials, but studying from them can be scattered: videos in one place, notes in another, and no easy way to share what you learned. We brought those pieces together as courses with notes attached to each video, so one learner's work could help the next.
A three-person team, where I owned the technical decisions
I was co-founder, CEO and lead programmer of a team of three. That meant deciding the data model, owning payments end to end, and reviewing everything that shipped. Firebase helped us move quickly. Its document database also meant we had to handle consistency and shared data differently from a relational database.
One database read per screen, by design.
Wozzii runs on a document database, and the data model was my call: each screen should load from a single document. A note carries its author's name and photo, and a course carries its whole video list, so showing every public note on a video costs no extra fetch. The counters that must stay exact, like how many times a course was copied into a learner's own list, sit behind atomic increments and a transaction I wrote. Cloud Functions keep the search index in step.
I implemented pay-what-you-want subscriptions on Stripe.
I built the payment flow end to end on Stripe. The learner typed the price they wanted to pay, the app opened a checkout for exactly that amount and started the subscription from it, and they could later change the card or cancel without going through us. Pay what you want was the product's whole promise, so the number a learner typed had to reach the charge intact, and a failed renewal had to be recoverable without an email to support.
I developed a points system to bring learners back.
We wanted to encourage a study habit, so the product rewarded participation. A learner earns points for the minutes they watch, for every note they write, and for finishing the onboarding. The number moves on screen the instant it is earned, credited into the profile copy the app keeps in memory, while the write reaches the database in the background as a single instruction that adds to the total instead of overwriting it, so two tabs cannot undo each other.
What a three-person team shipped
Three of us shipped a running product: scattered videos organized into courses, notes attached to the video they belong to, search across all of it, and subscriptions where the learner named the price. Over two hundred people used it, built more than twenty courses and left more than three hundred notes behind for whoever came next. The payments and the data model were mine, and I still stand behind the shape we gave it.
I can build a complete product, payments included, and I learned to validate that people are willing to pay before building the billing.