Choose your path
Pick a path to real Java mastery and start - your progress is saved right here on this device.
Zero to Java Engineer
The complete Java language & platform.
Seven progressive stages that take an absolute beginner all the way to a fully knowledgeable Java engineer.
The Spring Path
From Java engineer to Spring professional.
Master the full Spring ecosystem - the IoC container, Boot, web APIs, data, security, testing, reactive, and cloud - by building one real application, module by module.
Assumes the Core Java path (or equivalent working Java knowledge). Spring builds directly on OOP, generics, collections, and build tools.
The Interview Path
From Java engineer to interview-ready.
Data structures and algorithms in Java, taught pattern by pattern - complexity, arrays and strings, linked structures, hashing, trees, graphs, heaps, recursion and dynamic programming - plus the interview itself: system-design basics and how to communicate under pressure.
Assumes the Core Java path (or equivalent). You should be comfortable with classes, generics, collections, and recursion before drilling algorithms.
The Architecture Path
From engineer to senior: judgment, not just APIs.
The senior engineer's toolkit: SOLID and design patterns applied to real code, domain-driven design, hexagonal and clean architecture, the modular monolith, API and contract design, evolutionary architecture, and practical system design - taught by refactoring a deliberately messy codebase, module by module.
Assumes the Core Java path complete; the Spring path is strongly recommended. This is senior-level material about design judgment, not syntax.
Kotlin for Java Developers
From Java engineer to polyglot JVM engineer.
Kotlin taught as a Java developer's second language and a first-class JVM citizen - interop first, Android out of scope. Seamless Java interop, syntax for Java eyes, null safety, data and sealed classes, functional collections, coroutines, and Kotlin with Spring Boot - learned by re-implementing BookVault in Kotlin and diffing it against the Java you already know.
Assumes the Core Java path (or equivalent working Java). This is explicitly not a from-zero course - it teaches Kotlin by contrast with the Java you already know.