Learning paths

Not sure what to learn next? Pick your goal and follow the lessons in order. Every path is free, and your progress is saved in this browser.

Beginner25 lessons, 1 h 19 min reading

Java from zero

You have never programmed, or you are new to Java.

Install Java and write real programs, then learn objects, collections and the modern Java basics every job expects.

Start: How Java runs: JDK, JRE and JVM See all steps

Intermediate33 lessons, 1 h 41 min reading

Job-ready backend developer

You know the Java basics and want to build and ship REST APIs.

Everything between "I know Java" and "I can build a production Spring Boot service": tools, testing, databases, Spring and deployment.

Start: equals(), hashCode() and the Object contract See all steps

Intermediate to advanced28 lessons, 1 h 28 min reading

Crack the Java interview

You have a Java developer interview coming up.

The topics interviewers ask about most, from equals and HashMap internals to concurrency, data structures, Spring and system design.

Start: equals(), hashCode() and the Object contract See all steps

Intermediate15 lessons, 46 min reading

Upgrade from Java 8 to Java 25

You work on an older codebase and want to use modern Java.

What changed after Java 8 and how to use it: var, switch expressions, text blocks, records, pattern matching, the HTTP client, modules and virtual threads.

Start: Variables and data types See all steps

Advanced18 lessons, 54 min reading

Microservices and production

You build services that have to scale and stay up.

Service boundaries, gateways, messaging, resilience, sagas, caching, background jobs, containers and CI/CD.

Start: Auto-configuration and starters See all steps

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