A few weeks ago I wrote about mutation testing for Java with PIT: why 100% line coverage can still catch nothing, and how deliberately injecting small bugs, mutants, measures whether your tests wou...

Your Angular service reads courseName off every response. Last Tuesday the backend renamed that field to name. Both projects compile. Both test suites are green. Production shows a table full of bl...

Your architecture diagram says controllers never touch the repository directly. Your codebase disagrees. It happens quietly. Someone is in a hurry, injects a CourseRepository straight into a contr...

You have 100% line coverage for unit testing. A bug ships anyway. It happens because line coverage measures which lines of code your tests execute, not whether your tests are actually capable of d...

Prompt-first AI work is great for exploration. It is not enough for delivery. When the work starts to matter, the questions change. We need to know what the feature is supposed to do, what is out ...

This is lesson 15 of the Modern Angular Course. In the previous lesson, we used computed() to filter products reactively. Now we add child-to-parent communication so clicking “Add to Cart” in a pro...

Spring Boot 4 is not a routine version bump. This migration touches platform baselines (Java/Jakarta/Servlet), dependency structure, test infrastructure, and JSON behavior — all at once. If your ...

This is lesson 14 of the Modern Angular Course. In the previous lesson, we introduced a writable signal for the search input. Now we build on that foundation by deriving filtered state with compute...

Many teams are still using AI like an intern. We give instructions, review every output, request fixes, and repeat. It works for quick experiments. It does not work as a long-term delivery model. ...

This is lesson 13 of the Modern Angular Course. In the previous lesson, we used @if and @else to conditionally render UI in the product card. Now we turn to user interaction by adding a search inpu...

This is lesson 12 of the Modern Angular Course. In the previous lesson, we passed product data from the parent component to child cards using the modern input() API. Now that each card receives rea...

This is lesson 11 of the Modern Angular Course. In the previous lesson, we rendered a list of products using signals and @for. Each card still shows placeholder content. Now it is time to connect r...