- Spring Study Guide – Security
Authentication, authorisation, and the filter chain that implements both. How a request travels through the filters, what the SecurityContext holds and how it is cleared, password hashing and salting, matcher ordering and the mistake that silently opens an endpoint, method security with @PreAuthorize, stateless JWT auth, and the lambda DSL that replaced every old configuration answer.
- Eclipse Hot Keys
Learning your IDE's shortcuts is one of the highest-return investments a developer makes, because the saving is small and repeated thousands of times. This is the Eclipse set worth memorising, with the IntelliJ equivalent alongside — most teams have both. Windows and Linux bindings are given first;…
- 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.
- Breadth-First Search
Explore level by level using a queue — and get the shortest path in an unweighted graph for free, which no other traversal does. Reconstructing the path, why you mark visited on enqueue rather than dequeue, and where BFS stops being the right tool.
- Spring Boot – Cheat Sheet
The annotations and snippets from this whole track in one page, grouped by what you are trying to do — wire a bean, expose an endpoint, query a database, secure a route, cache a result, schedule a job. Written to be scanned rather than read, with a link to the lesson behind each one.