Java Backend Developer · with AI

Become a Java backend developer — in the age of AI, with AI by your side.

A structured course, an AI mentor that hints instead of solving, and code written in your own IntelliJ. You learn to think like an engineer, not to copy ready-made answers.

Create account See the course

IntelliJ IDEA pluginVAT invoice

OrderService.java

// Task: compute the order total
public BigDecimal total(List<Item> items) {
  return items.stream()
    .map(Item::price)
    .reduce(BigDecimal.ZERO, BigDecimal::add);
}

AI mentor Good — but what if the list is empty? Check what reduce returns and whether that is acceptable for an order.

Why Yocora

Most courses teach syntax. We teach you to think like a backend developer — and to use AI without fooling yourself.

How it works

Every lesson is one complete learning loop

No hours of video. You go through four steps that together build a real skill — and proof that you have it.

Theory

A short, focused lesson. No walls of text — just enough to move forward.

Quiz

You check that you understand before moving to code. The pass threshold catches gaps.

Coding task

You write real code. Public tests guide you, private tests verify you.

Homework

A larger project with automated grading. This is where what you just learned sticks.

AI that teaches

The AI mentor hints — it does not solve it for you

Prompt sessions and agent sessions are not a chat with a ready answer. The model guides, asks questions and explains, while you make the decisions. You learn to judge the tool’s answers — a skill the market demands today.

A hint instead of a ready-made solution
An agent walks you step by step through harder tasks
You learn when to trust AI and when to verify it

You

My test fails on an empty list. What am I doing wrong?

AI mentor

I will not tell you outright. Pause at the total() method: what does reduce return for an empty stream? Does that value make sense as an order amount? Start there.

A real workshop

You code in your own IntelliJ — not a toy editor

The Yocora plugin connects the course with IntelliJ IDEA. You practice in the tool you will later use professionally, and your progress syncs automatically.

Tasks and tests run locally in the IDE
Progress and practice time sync with the platform
Sign in with a personal token — no password in the plugin

intellij · yocora plugin

// tests: 7/8 green
✓ sums multiple items
✓ ignores duplicates
✗ empty list → expected 0.00

Course outline

From zero to a backend application

A full, transparent path — you know exactly what you will learn and in what order. No "job guarantees", just a concrete plan.

Phase I — Programming Foundations

Orientation and Developer Setup · 5 lessons

How the Internet and Web Apps Work
What Backend Developers Actually Do
Java Ecosystem Overview
Developer Environment Setup
First Java Program

Java Fundamentals · 8 lessons

Variables and Primitive Types
Operators
Control Flow
Loops
Methods
Arrays
Strings
Input and Output Basics

Object-Oriented Programming · 9 lessons

Classes and Objects
Constructors
Encapsulation
Inheritance
Polymorphism
Interfaces
Abstract Classes
Composition vs Inheritance
SOLID Intro

Collections and Modern Java · 10 lessons

List
Set
Map
Generics
Exceptions
Enums
Records
Optional
Lambda Expressions
Stream API

Algorithms and Problem Solving · 7 lessons

Big O Basics
Arrays and Hashing
Two Pointers
Recursion Basics
Sorting and Searching
Stack and Queue Basics
Backend-Oriented Problem Patterns

Phase II — Professional Backend Development

Git and Team Workflow · 6 lessons

Git Fundamentals
Branching
Merge and Rebase
Pull Requests
Conventional Commits
Git Workflows

Networking Fundamentals for Backend Engineers · 13 lessons

How Data Travels Through a Network
TCP/IP and the Practical OSI Model
IP Addresses, Ports and Sockets
Network Interfaces, Localhost and Binding
Routing, NAT and Firewalls
DNS Resolution
TCP Connections and Reliability
UDP and Datagram Communication
Network Programming with Java Sockets
Message Framing and Protocol Design Basics
TLS, HTTPS and Certificates
Proxies, Reverse Proxies and Load Balancers
Network Debugging with curl, dig, netstat and Wireshark

HTTP, Web Protocols and API Design · 25 lessons

HTTP Architecture and Message Structure
URLs, URIs and Request Targets
HTTP Methods and Semantics
HTTP Headers and Content Negotiation
Request and Response Bodies
Cookies and Sessions
HTTP Caching and Conditional Requests
Connection Lifecycle and Keep-Alive
HTTP/1.1 Framing
HTTP/2 Multiplexing
HTTP/3 and QUIC Intro
REST Principles
Resource Modeling
Endpoint Design
Status Codes
Error Response Contracts
Idempotency
Pagination
Filtering and Sorting APIs
API Versioning
Webhooks
WebSockets
Server-Sent Events
API Documentation
HTTP Traffic Debugging

Spring Boot Fundamentals · 9 lessons

What Spring Does
Inversion of Control
Dependency Injection
Spring Boot Project Structure
Configuration Files
Beans and Lifecycle
Controllers
Services
Repositories and DAO Context

Building REST APIs with Spring Boot · 9 lessons

Creating REST Controllers
Request Mapping
Path Variables
Request Bodies
DTOs
ResponseEntity
Validation
Global Exception Handling
Clean Controller Design

SQL and Relational Databases · 10 lessons

Relational Model
Tables and Keys
SELECT Queries
INSERT UPDATE DELETE
JOINs
GROUP BY
Aggregates
Subqueries
Indexes
Transactions Basics

Spring Data JPA and Hibernate · 15 lessons

ORM, JPA, Hibernate and Spring Data
Entity Mapping Fundamentals
Schema Generation and Database Migrations
Persistence Context and Entity Lifecycle
Transactions, Dirty Checking and Flush
Many-to-One and One-to-Many
One-to-One
Many-to-Many and Association Entities
Spring Data Repositories
Derived Queries
JPQL and @Query
Projections and DTO Queries
Pagination and Sorting with JPA
Fetching Associations
N+1 Problem and Fetch Plan Design

Testing · 8 lessons

Why Testing Matters
JUnit Fundamentals
Unit Tests
Mockito
Integration Tests
Testing Controllers
Testcontainers Intro
Coverage and Test Quality

Security and Authentication · 17 lessons

Security Basics
Password Hashing
Authentication vs Authorization
Cookies, Sessions and Browser Security
CSRF Protection
CORS and Same-Origin Policy
JWT Fundamentals
Spring Security Basics
Roles and Permissions
OAuth 2.0 Fundamentals
OpenID Connect
Authorization Code Flow and PKCE
Refresh Tokens
Token Rotation and Revocation
Secure API Design
TLS, mTLS and Service Authentication Intro
OWASP Top Risks Intro

Phase III — Advanced Backend Engineering

Advanced Java for Professionals · 13 lessons

Concurrency Basics
Threads and Executors
CompletableFuture
Synchronization Basics
Blocking vs Non-Blocking I/O
Java NIO, Channels and Buffers
Selectors and Multiplexed I/O
Virtual Threads
Reactive Programming and Backpressure Intro
Spring MVC vs WebFlux
JVM Memory Model Intro
Garbage Collection Basics
Performance Profiling Intro

Advanced SQL and Data Modeling · 7 lessons

Database Design
Normalization
Denormalization
Query Optimization
Execution Plans Intro
Stored Procedures Basics
Locking and Isolation

Architecture and Design Patterns · 9 lessons

Layered Architecture
Hexagonal Architecture Intro
Repository Pattern
Strategy Pattern
Factory Pattern
Builder Pattern
API Gateway and Backend for Frontend Intro
Synchronous vs Asynchronous Communication
Event-Driven Concepts Intro

Service Communication and Messaging · 15 lessons

Backend Applications as Network Clients
Java HttpClient
Spring RestClient
Spring WebClient
Timeouts and Connection Pools
Retries, Exponential Backoff and Jitter
Idempotent Service Communication
Circuit Breakers, Bulkheads and Fallbacks
gRPC and Protocol Buffers
Messaging Fundamentals
RabbitMQ and AMQP
Kafka Fundamentals
Consumer Groups, Ordering and Partitioning
Delivery Guarantees and Duplicate Handling
Dead-Letter Queues and Poison Messages

Docker, Networking and Deployment · 14 lessons

Containers Fundamentals
Dockerfiles
Docker Compose
Environment Variables and Secrets
Container Networking
DNS and Service Discovery in Docker
PostgreSQL in Containers
Container Registries and Image Versioning
Reverse Proxies with Nginx
TLS Termination
CI/CD Deployment Pipeline
Deploying Spring Apps
Logging in Containers
Monitoring Containerized Applications

Production Engineering · 15 lessons

Error Handling in Production
Structured Logging
Metrics Basics
Health Checks
Rate Limiting Intro
Caching Basics
Resilience Patterns
Distributed Tracing
Correlation IDs and Request Context
Load Balancing Fundamentals
Graceful Shutdown and Connection Draining
Backpressure and Capacity Limits
Diagnosing Timeouts and Connection Pool Exhaustion
Debugging 502, 503 and 504 Errors
Production Incident Debugging and Runbooks

Phase IV — AI for Backend Developers

AI Foundations for Engineers · 7 lessons

What LLMs Are
Tokens and Context Windows
Prompts
Temperature and Sampling
Hallucinations
Model Selection
Cost Fundamentals

Integrating AI with Java Applications · 7 lessons

Calling Model APIs
Sending Prompts from Backend
Parsing Responses
Designing AI Service Layers
Error Handling for AI APIs
Prompt Templates
Guardrails Basics

Retrieval and RAG Basics · 6 lessons

What is RAG
Embeddings Intro
Vector Search Concepts
Retrieval Pipeline
Chunking Basics
RAG Design Tradeoffs

AI Product Features · 6 lessons

Classification with LLMs
Extraction Workflows
AI Recommendations
Chat Backends
AI Feature Evaluation
Cost Control in AI Products

Phase V — Portfolio Systems

Project: Task Management Platform

Project: E-Commerce Backend

Project: AI SaaS Backend

Phase VI — Career Preparation

Interview Preparation · 6 lessons

Java Interview Topics
Spring Interview Topics
SQL Interview Topics
System Design Intro
Backend Coding Interviews
CV and GitHub Portfolio

You finish every module with working code, not just theory.

Who it's for

Yocora is for you if…

You are switching careers

You want to enter tech on a clear path, not wander through random tutorials. Yocora gives you a plan from zero to a backend project.

You are a junior

You know the basics but want a solid backend: Spring, databases, tests. And to learn to work with AI the way teams do.

You are going full-stack

You handle the front end and the other half is missing. Complete the picture: APIs, persistence and server-side architecture.

Progress and motivation

You can see yourself moving forward

Learning sticks when you see results. Yocora shows your progress and helps you keep the rhythm.

Learning streaksBadgesStudy plannerSkill roadmapCompletion certificate

FAQ

Frequently asked questions

Do I need prior programming experience?

No. The course starts from the basics and walks you step by step up to backend projects. If you already code, you will move through the intro module faster.

What is the "AI mentor"?

Prompt sessions and agent sessions teach you to work with AI: the model hints, guides and explains, but does not paste a ready-made solution. You learn to judge the tool’s answers — a skill the market demands today.

Where do I write the code?

In your own IntelliJ IDEA. The Yocora plugin syncs your progress, so you practice in a real working environment, not a toy editor in the browser.

Can I pay in installments?

Yes. You can buy the course in one payment or split it into 3, 6 or 12 installments. It is the same full price — installments only spread it over time.

Will I get an invoice?

Yes. At checkout you can provide a tax ID and company details — a VAT invoice is generated automatically.

How does Early Bird differ from Standard?

It is the same full course. Early Bird is the launch price available to a limited number of seats; Standard is the regular price after the launch ends.