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PickNTech

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Pick a tech.
Teach yourself.

Choose any technology and learn it on your own, at your own pace. Clear roadmaps, code-first lessons, exercises and interview questions — everything you need, in the right order.

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Java Developer

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JavaOOPSpring BootYOU ARE HERESecurityDockerAWS

How you learn

A loop that turns reading into skill.

  1. 01

    Learn

    Short, code-first lessons that explain the why, not just the syntax.

  2. 02

    Practice

    Exercises and interview questions at the end of every lesson.

  3. 03

    BuildSoon

    Guided, production-style projects that tie the skills together.

  4. 04

    Master

    Track progress across roadmaps and see exactly what’s next.

Roadmaps

Choose your developer journey.

Structured paths from zero to job-ready. Every node links to real lessons.

All roadmaps →

Java Full Stack

From your first Java class to a deployed, secured Spring Boot API with a database and a frontend.

Java → Spring Boot → SQL → Angular → Docker → AWS

12 skills13 lessonsBeginner
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Backend Developer

APIs, databases, caching and deployment — the core of server-side engineering.

Java → Spring Boot → SQL → Docker

6 skills8 lessonsBeginner
Explore
Soon

Frontend Developer

HTML, CSS, JavaScript and a modern framework — build interfaces people enjoy.

HTML → CSS → JavaScript → React → Angular

3 skillsBeginner
Soon

Python Developer

From scripting to web services and data work with Python.

Python → SQL → Docker

4 skills2 lessonsBeginner
Soon

DevOps Engineer

Containers, CI/CD, cloud and observability.

Docker → Kubernetes → AWS

3 skills1 lessonsIntermediate
Soon

System Design

Scalability, trade-offs and the building blocks of large systems.

Caching → Queues → Databases → Load balancing

1 skillsAdvanced

Your learning journey

See where you’re going.

Stop wondering what to learn next. Every roadmap shows what you’ve finished, where you are, and what comes after — and it updates as you complete lessons.

✓
Completed
◉
You are here
●
Available
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Coming soon
Open the Java Full Stack roadmap →

Java Full Stack

  1. Java FundamentalsYou are here
  2. Object-Oriented Programming
  3. Collections
  4. Java 8+
  5. Spring Boot
  6. REST APIs
  7. SQL
  8. Spring Security
  9. Angular
  10. Docker
  11. AWS
  12. Final Project

Pick a tech

What do you want to teach yourself?

Every technology is a self-paced course. Pick one, start anywhere, learn at your own speed.

JvJavaSbSpring BootSqSQLDkDockerJsJavaScriptPyPythonNgAngularReReactAwAWSK8KubernetesSdSystem Design

Practice what you learn

Don’t just read code.
Break it. Fix it.

Every lesson ends with exercises and interview questions, so you find the gaps in your understanding before an interviewer does.

EvenNumbers.javaWon’t compile
List<Integer> nums = List.of(1, 2, 3, 4);

List<Integer> evens = nums.stream()
    .filter(n -> n % 2)
    .toList();

What’s wrong?

Blog

From the developer blog.

Deep dives written for developers who want to understand, not memorise.

All articles →

Spring Boot

How to Structure a Spring Boot Project (That Still Makes Sense in a Year)

Package-by-layer vs package-by-feature, where DTOs and mappers belong, and a folder structure that scales from one controller to fifty.

2 min read · 25 Sept 2026Read

Java

Java Streams in Practice: 10 Patterns You'll Use Every Day

The stream recipes that show up again and again in real backend code — grouping, lookups, deduplication, pagination and the mistakes to avoid.

2 min read · 24 Sept 2026Read

Java

How HashMap Works Internally in Java

Buckets, hashing, collisions, treeification and resizing — the HashMap internals every Java interview asks about, explained simply.

3 min read · 18 Sept 2026Read

Pick a tech. Teach yourself.

No teacher, no schedule, no account. Your first lesson takes 10 minutes, and your progress is saved as you go.

Pick a tech →Start with Java