- Frontend Dev – Talking to the Backend
One request has four outcomes and beginners handle one of them. Building a single API layer instead of scattering fetch calls, turning an error response into something a component can render, loading and error and empty states, cancelling a request that no longer matters, and why CORS fails the way it does.
- Database
JDBC is the API every Java database access sits on — Hibernate, Spring Data, jOOQ and every ORM eventually call it. You will rarely write it directly, and knowing what it does is what lets you diagnose the layers above it. The shape Four objects: a Connection to the database, a PreparedStatement…
- Spring Study Guide – Web Layer
Spring MVC end to end. What the DispatcherServlet does with a request, the six delegates it hands off to, how a URL reaches a method, the controller method parameters and return types worth knowing, the Model and where the view gets it, view resolution, the web scopes, and why the whole design is testable without a servlet container.
- Regex
A regular expression describes a pattern of text. Java's support lives in java.util.regex , and the hardest part is not the syntax — it is knowing when a regex is the right tool and keeping the ones you write readable. The three ways in Compile the pattern once if it is used more than occasionally.…
- 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.