For frontend developers

See the whole picture.

You build great UIs. Now understand the systems behind the APIs you call. Interactive exercises that teach backend architecture through the lens of a frontend developer.

Start the System Design Course

Why your API is slow

Learn how databases, caches, and load balancers affect the response times your UI depends on. Debug performance from the full stack.

Backend concepts, explained clearly

Distributed systems, message queues, replication. Each concept explained through exercises you can complete in your browser.

Talk to your backend team

Speak the same language as your backend engineers. Contribute to architecture discussions instead of waiting for API specs.

System Design + Flutter + SOLID

Full-stack understanding for frontend-first developers.

Try a Lesson

Write code from lesson one

Every lesson is an exercise you solve in your browser. Real code, real tests, real feedback.

Write a greeting function

main.ts

function greet(name: string) {

return `Hello, ${name}!`

}

Structured progression

Each concept builds on the last. You always know what to learn next.

Multiple exercise types

Quizzes, fill-in-the-blank, matching, and code keep every lesson engaging.

Instant feedback

Submit your answer and see test results in milliseconds.

Learn by doing

Solve exercises in your browser from the first lesson.

Try a Lesson

Join over 5,000 learners

Flutter Zero to Mastery

Explore our courses

Pick a course and solve your first exercise.

Programming And Computers

Learn the principles of how programming and computers work.

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TypeScript

Learn TypeScript from variables to generics, with coding challenges you solve directly in your browser.

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Electricity and Current

Learn how electricity works, from voltage, current, and resistance to circuits, Ohm's law, and common components like resistors, LEDs, and capacitors.

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Microcontrollers

From GPIO pins and breadboard circuits to sensors, displays, motors, and communication protocols like I2C, SPI, and UART.

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System Design

Learn how APIs, databases, caching, and load balancing fit together to build scalable systems.

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Dart

An interactive Dart course where you code, test, and build apps directly in your browser.

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Flutter

An interactive Flutter course where you code, test, and build apps directly in your browser.

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S.O.L.I.D Principles in OOP

Learn the principles of how software should be structured, so you can guide AI to build better systems.

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D.R.Y. (Don't Repeat Yourself)

Learn to identify and eliminate code duplication, making your codebase cleaner and easier to maintain.

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Interactive courses

Every lesson is an exercise with instant feedback.

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Great frontend developers understand the backend.

Interactive system design for UI-first engineers.

Get Started