- Angular – Directives
A directive is a component without a template — behaviour you attach to an element you did not write. The built-in attribute directives, writing your own with `@Directive` and an attribute selector, why the work belongs in `afterNextRender` rather than the constructor, input transforms with `booleanAttribute`, and where `host` bindings and `hostDirectives` fit.
- Docker – Writing a Dockerfile
The instructions that actually matter: `FROM`, `WORKDIR`, `COPY`, `RUN`, `ENV`, `EXPOSE`, `USER`, and the `CMD` versus `ENTRYPOINT` distinction that trips up everyone once. Built up line by line into the real Dockerfile that produces the pizza API image.
- Hasura – What It Is and Why It Exists
Start here. What Hasura actually does — point it at a Postgres database and get a GraphQL API with filtering, pagination, relationships and permissions without writing a resolver — and, just as important, what it does not do. Why v2 and v3 (DDN) are two different products rather than two releases of one, the exact versions this track is written against, the booking app every example comes from, and the full lesson index in reading order.
- React – Conditional Rendering
Four ways to render something only sometimes — if before the return, the ternary, &&, and returning null — and when each one reads best. Includes the && trap that renders a literal 0 on the page, and the early-return pattern that guards a whole route.
- Java String
String is the type you will use more than any other, and it has one property that explains nearly all of its behaviour: a String is immutable . Once created, its characters can never change. Every method that appears to modify a string actually returns a new one. Immutability, and what it means in…