Web platform
algopath.pro
Learn algorithms by building them: 150 steps, 6 languages, code runs in the browser.
An active-recall course for data structures and algorithms, in English and Russian. Every step is one arc: the theory, your own implementation, then the same algorithm inside a real production case. Binary search shows up as git bisect, a sliding window as a rate limiter. Code runs in the browser in 6 languages, nothing executes on the server. Freemium with Stripe billing.
What I did
Course, platform, code runner, billing and the site.
- Wrote the course: 150 steps in English and Russian, each with theory, an exercise with tests, and a production case.
- Built the platform on Laravel and Inertia with React: progress, leaderboard, pattern trainers, timed mock interviews.
- Made the code runner client-side for all 6 languages: JavaScript and TypeScript in a Web Worker, Python through Pyodide, PHP through php-wasm, Java through CheerpJ, C# on a .NET WebAssembly runtime.
- Added freemium access with Stripe: the first 33 steps free, the rest server-side until purchase, lifetime or subscription.
- Set up CI on every push, Playwright before push, and a deploy that renders the production env from secrets and syncs over SSH.
- Built the admin panel: courses, blog, newsletter, coupons, roles and permissions.
The decisions, and why
- Code runs in the browser
- A server that executes strangers' code is a security job of its own and a bill that grows with every learner. WebAssembly runtimes make the tab do the work, and the server stays a content server.
- Implementation before explanation
- Watching an algorithm explained does not survive interview stress. Credit is earned by writing the core yourself and saying out loud why it fits the case.
- Locked steps stay on the server
- A paywall in the client is a paywall for people who do not open developer tools. The lesson body, hints and exercise of a locked step never reach the browser.
- Two languages, one source
- The Russian and English courses are the same steps in two folders, and the platform seeds its database from them. One fix lands in both.
Built with
- Laravel
- Inertia
- React
- TypeScript
- MySQL
- WebAssembly
- Stripe
The numbers, and where they come from
- PageSpeed, mobile
- 98
- PageSpeed Insights, 12 Sep 2026
- Steps in the course
- 150
- English and Russian
- Languages you can solve in
- 6
- JS, TS, Python, PHP, Java, C#
- Pages
- 177
- sitemap, 9 Sep 2026
Performance scores move a few points between runs on any site, including these. Paste the address into PageSpeed Insights and run it yourself.
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