- React Native – TextInput and Forms
`TextInput` is where a mobile app is won or lost. `keyboardType` and `textContentType` change the keyboard itself and unlock password autofill; `autoCapitalize="none"` on an email field is the single most common React Native bug. Controlled inputs, validation without a form library, per-field errors, and submitting from the keyboard when there is no Enter key.
- Spring Boot – Building a REST API
@RestController end to end: path and query binding, request bodies, Bean Validation, and returning the right status code instead of 200 for everything. Why the pizza API exposes a UUID rather than its primary key, and why a DTO is not ceremony once an entity has a password field on it.
- Python – Get Started
Start here. Install Python, run your first script, and understand the difference between the REPL and a file. Which Python version this track uses and why, every major 3.x release and what each one added, virtual environments and pip, and the map of the other 25 posts with the order to read them in.
- Java Interface
An interface is a contract: a list of methods a class promises to provide, with no state and (mostly) no implementation. It is the main tool Java gives you for writing code that does not depend on a specific class — and that is what makes code testable and changeable. Declaring and implementing one…
- React – Handling Events
onClick takes a function, not a call — the single most common beginner mistake, and why the arrow function fixes it. Passing arguments to a handler, typing the event in TypeScript, preventDefault on form submits, and how event propagation differs from the DOM you already know.