- 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.
- Collectors class
A stream pipeline has to end somewhere. collect is the general-purpose ending, and the Collectors class supplies the recipes — turn this stream into a list, a map, a grouped report, or one joined string. There are dozens of them and you do not need dozens. Six do almost all the work in practice,…
- Omega, Theta and the Rest of the Notation
Big O is an upper bound, Omega is a lower bound and Theta is both at once. What each one actually claims, why saying an algorithm is O(n^2) does not mean it is slow, and the difference between a bound and a case that people conflate constantly.
- React – Forms and Controlled Inputs
A controlled input is one whose value comes from state, which is what makes validation, formatting and disabled submit buttons possible at all. value plus onChange, one handler for many fields, checkboxes and selects and radios, submitting without reloading the page, and useId for labels that actually work.