- Heaps
A tree stored in a flat array with no references at all, kept ordered just enough that the minimum is always at index 0. Sift up, sift down, and why building a heap from an array is O(n) rather than O(n log n) — a genuinely counter-intuitive result.
- React – Code Splitting with lazy and Suspense
Everything imported at the top of your app ships to every visitor, including the admin screens 99% of them will never open. lazy turns an import into its own bundle fetched on demand, Suspense says what to show while it is in flight, and the route boundary is where to draw the line. With before-and-after bundle numbers.
- Angular – Testing
Testing a pipe, a directive, a guard and an HTTP interceptor. When you need `TestBed` and when `new MyPipe()` is the better test, hosting a directive to exercise its selector, `HttpTestingController` and why `verify()` matters, driving a debounced search with fake timers, and where Playwright takes over from unit tests.
- Docker – Multi-Platform Builds and exec format error
You build on an Apple Silicon Mac, you push, the server says `exec format error`. Why that happens, what buildx and QEMU do about it, `--platform` for one target and a manifest list for both, what emulated builds cost in time, and the `--platform=$BUILDPLATFORM` trick that makes a cross build fast again.
- Hasura – Logging, Metrics and Tracing
Knowing what your API is doing once real traffic hits it. The log types Hasura can emit and which ones are worth turning on, reading a query log to find the slow operation rather than guessing, the health and metrics endpoints, and tracing a request across Hasura and the service behind an Action. Plus what changes in v3.