Learn Java Concurrency
Threads, locks, and race conditions, made deterministic. Built for backend engineers writing multithreaded code. You write real Java, run it in the browser, and watch it pass. No installs, no toy apps, no lectures.
11 projects, 275 hands-on levels, first project free.
Problems you will solve
- coordinate threads safely
- eliminate a race condition
- use thread pools and futures
By the end you can write correct concurrent Java.
What you will build
- Foundations: code through concurrency
- Threads & Runnables
- Shared State & Races
- Synchronization
- Atomics & CAS
- The Java Memory Model
- Executors & Thread Pools
- Coordination & Synchronizers
- Concurrent Data Structures
- Hazards & Patterns
- Capstone: A Concurrent Job System
Start the Concurrent Programming track free.
Frequently asked questions
Do I need to know how to code to start Concurrent Programming?
No. The Concurrency in Java track starts from the fundamentals and builds up, and the first project is free.
Do I need to install anything?
No. Every level runs in your browser and is graded the moment your code works. No Java install, no setup.
What language will I write?
Java. You write real Java, run it, and get instant feedback across 275 hands-on levels.
Is it free to start?
Yes. The first project is free with no card. Unlimited access to all 33 tracks is $12 a month or $100 a year.