- React Native – Structuring a Real App
The folder layout that survives a second developer. Feature-first rather than type-first, why route files should name a screen and never implement one, path aliases so nothing imports `../../../`, a single shared type contract with the backend, and the rule that keeps it honest: anything two features need moves down, never sideways.
- TypeScript – any, unknown, never and void
The four types that are not values. any switches the checker off and spreads; unknown is the safe version and forces you to prove what you have; never is what a function that does not return has, and the trick behind exhaustive switches; void is not undefined. With the catch (err: unknown) block that made the case.
- NestJS – Modules
The unit Nest is organised around. What imports, providers, controllers and exports each mean, why a provider is private to its module until you export it, when @Global() is right and why it is used exactly once in this app, and how forRoot/forFeature dynamic modules differ from ordinary ones.
- Array Parallel Sort
Arrays.parallelSort sorts an array using every core on the machine instead of one. It is a single-word change from Arrays.sort , which makes it tempting to use everywhere — and it is slower than the sequential version on most of the arrays you will actually sort. Using it Like Arrays.sort , it…
- Linked Lists
Nodes joined by references. O(1) at the front where an array is O(n), O(n) for random access where an array is O(1) — the trade in both directions. Reversing a list in one pass, Floyd's cycle detection, and why the tail reference matters.