- Optional
Optional is a container that either holds a value or is empty. Its purpose is not to eliminate null — it is to move "there might be nothing here" out of your head and into the type signature, where the compiler and the next reader can both see it. The problem it solves Nothing forces a caller of…
- Terraform – What It Is and Why It Exists
Start here. What infrastructure as code actually buys you over clicking around a console, where Terraform sits next to CloudFormation, CDK, Pulumi and Ansible, the 2023 licence change and what OpenTofu is, the exact versions this track is written against, the application the AWS lessons deploy, and the full lesson index in reading order.
- React Native – Navigation
Navigation is not a router over URLs — it is a stack of native screens. Expo Router makes the folder structure the navigation graph: `(tabs)` groups without adding a URL segment, `[orderId]` declares a dynamic route, `+not-found` catches the rest. Stacks versus tabs, passing and reading params, `push` versus `replace`, and why route files should be one line long.
- TypeScript – Setting Up a Project
Two projects, two setups, and the difference matters. A Node service where tsc emits the JavaScript, and a Vite app where tsc only checks and the bundler strips the types. What tsc --init actually gives you, why noEmit is not a downgrade, and the four commands you will run every day.
- NestJS – Get Started
Start here. What NestJS actually is — a structure for a Node server, not a runtime — why it looks like Angular and Spring, when the structure earns its cost and when it does not, the exact versions this track is written against, the contractor marketplace API every example is taken from, and the full lesson index in reading order.