Backend Development Tutorials

What a Java backend engineer actually does, and what you need to learn to become one — the language, the framework, HTTP and API design, databases, authentication, caching and async work, testing, and getting it deployed and observable. Every example is real Java 21 and Spring Boot 4.1 code from a working pizza ordering API.

• Backend Dev – Deployment and Observability
  Code that only runs on your laptop is not finished. Building one artifact and configuring it per environment, secrets that are not in git, containers and what they actually fix, a deploy pipeline, health checks the load balancer can use, and logs, metrics and traces — enough to answer “is it broken and where” at 3am.
• Backend Dev – Testing
  Tests are how you change code you did not write without being afraid. What is worth testing and what is theatre, unit tests that run in milliseconds, integration tests against a real database, testing the API through HTTP, test data that does not rot, and why chasing a coverage number produces a suite that catches nothing.
• Backend Dev – Caching, Async Work and Messaging
  Three ways to stop making the caller wait, and the cost of each. What is safe to cache and how to invalidate it, why the cache goes in front of the slow thing and not in front of everything, moving work off the request thread, events inside one process versus a real queue between services, and retries that do not double-charge anyone.
• Backend Dev – Authentication, Authorization and Security
  Who are you, and are you allowed to do that — two different questions that beginners merge into one. Password storage that survives a database leak, sessions versus stateless JWT and the trade you are making, OAuth2 login, checking permissions on the object and not just the endpoint, and the handful of attacks worth knowing by name.
• Backend Dev – Databases
  The part of the job that bites hardest and gets taught least. Modelling a schema you can live with, the indexes that decide whether a query takes 2ms or 2 seconds, what a transaction guarantees and what it does not, ORM versus plain SQL and when to drop down, the N+1 problem, connection pools, and migrations you can run on a live table.
• Backend Dev – HTTP and API Design
  The contract you hand to every other team. What HTTP actually gives you — methods, status codes, headers, idempotency — how to shape URLs and payloads so they survive the next feature, why a DTO is not busywork, validating input at the edge, one error format for the whole API, pagination, and versioning before you need it.
• Backend Dev – What to Learn in a Framework
  Frameworks look enormous, but the part you use every day is small and it is the same part in every framework. Project layout, dependencies, configuration and profiles, dependency injection and why it is not just a fashion, the request path from URL to method, and how to tell a framework problem from your own bug.
• Backend Dev – The Java and the JVM You Actually Need
  You do not need all of Java before you start a framework, but you do need a specific subset — and one that is not the subset a beginner course teaches. Collections and which one to reach for, equals and hashCode, Optional, streams, exceptions that mean something, records, and the handful of JVM facts that explain your production bugs.
• Backend Dev – What a Backend Engineer Actually Does
  The job, described by what lands in your queue rather than by a job posting. What you own — the API contract, the data, correctness under concurrency, and what happens at 3am — where the line sits between you and frontend, devops, DBA and data engineering, and what a real ticket looks like from request to deploy.
• Backend Dev – Get Started
  Start here. What a backend engineer builds, the ten things you need to learn and the order to learn them in, and the exact stack every example in this track uses — Java 21 and Spring Boot 4.1. Also: how this track fits with the deeper ones on the site, so you know when to stop reading here and go read those instead.