Zero to Dev · Interactive backend courses

Learn backend development. One interactive lesson at a time.

Courses in Azerbaijani and English, starting with Java. You run the code yourself, pass a checkpoint after every part and check your homework against the expected output.

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Azerbaijani and English
Free preview: lessons 1–3
Every answer checked with JDK 25

Main.javaStep through code

for (int i = 1; i <= 5; i++) {
    System.out.println(i + " squared = " + i * i);
}

Variables

int i: 6
i <= 5: false
iterations: 5

Console

$ java Main1 squared = 12 squared = 43 squared = 94 squared = 165 squared = 25

Watch variables change line by line, like a debugger, and see exactly what Java does.

Courses

Pick a course. Start with the free lessons.

Each course is a path of short interactive lessons, grouped into modules. Open the free preview lessons without signing in.

Main.javafor (int i = 1; i <= 5; i++)

Beginner

Java Backend Course

From your first Java program to a deployed Spring Boot service: Java, SQL, Git, Spring, JPA, Security, testing and Docker.

Ravil YahyayevAuthor of the lessons

See the course Open a free lesson

lessons ready now: 5/ 56
free preview lessons: 3
checkpoint questions: 132
homework tasks: 41

The path, module by module

12 modules · 56 lessons · 5 ready now

01Java Fundamentals26 lessons · 5 ready
02SQL with PostgreSQL4 lessons · coming soon
03Git and Version Control2 lessons · coming soon
04Spring Framework4 lessons · coming soon
05HTTP and Web Fundamentals1 lesson · coming soon
06Spring Boot4 lessons · coming soon
07Spring Data JPA5 lessons · coming soon
08Spring Security3 lessons · coming soon
09Testing2 lessons · coming soon
10Docker2 lessons · coming soon
11Cloud Deployment1 lesson · coming soon
12Final Project2 lessons · coming soon

Ready now

01Introduction to JavaFree preview
02Primitive Data Types and VariablesFree preview
03Operators and ExpressionsFree preview
04Control Flow StatementsFor students of the course
05Loops and IterationFor students of the course

More courses are on the way.

Inside every lesson

Not videos to watch. Lessons you work through.

Every lesson is an interactive page. The pieces below are taken from the lessons themselves.

From lesson 1

Break it on purpose

Real compiler errors and their fixes, so the red text in IntelliJ stops being scary.

Main.java

public class Main {
    public static void main(String[] args) {
        System.out.println("Hello, World!")
    }
}

$ javac Main.java
Main.java:3: error: ';' expected
        System.out.println("Hello, World!")
                                           ^
1 error

FixAdd ; after the closing parenthesis.

public class Main {
    public static void main(String[] args) {
        system.out.println("Hello, World!");
    }
}

$ javac Main.java
Main.java:3: error: package system does not exist
        system.out.println("Hello, World!");
              ^
1 error

FixWrite System with a capital S.

public class Main {
    public static void main(String[] args) {
        System.out.println("Hello, World!);
    }
}

$ javac Main.java
Main.java:3: error: unclosed string literal
        System.out.println("Hello, World!);
                           ^
1 error

FixAdd the closing " before ).

From lesson 5

A checkpoint after every part

Short quizzes tell you right away whether you understood, with an explanation for every answer.

How many times does the body run?

for (int i = 1; i <= 64; i *= 2) {
    System.out.println(i);
}

Pick an answer to see the explanation.

From lesson 5

Homework in three levels

Warm-up, core and challenge tasks, each with the expected output so you can check yourself.

Warm-up
Core
Challenge

Sum and averageExpected output

With n = 10:

Sum: 55
Average: 5.5

With n = 7:

Sum: 28
Average: 4.0

Azerbaijani and English

Every lesson exists in Azerbaijani and English, and you can switch between them at any moment.

Checked with JDK 25

Every code output and every quiz answer is checked by running it with JDK 25.

Quizzes and exams

Checked by the server.

Progress on every device

Your progress is saved on every device.

How it works

Three steps to start.

A Google account and a class code from your teacher. That’s all it takes.

Sign in with Google
Use the same Google account you use for Google Classroom. No passwords to remember.
Enter your class code
Your teacher gives the class a code. Enter it once and the course opens.
Learn and check yourself
Work through the lessons, pass the checkpoints and quizzes. Your progress is saved on every device.

Free preview

Try the first lessons for free.

The first three lessons of the Java Backend Course open without signing in.

Open the first lesson See the course