- 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.
- Spring Boot – Messaging with JMS
Handing work to a queue so the request can return. JmsTemplate, @JmsListener, converting a message payload to JSON, and what to do with a message that keeps failing — because without a dead-letter destination it is redelivered forever.
- 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.
- Android – The Kotlin You Need First
Not the whole language — the parts an Android app leans on every day. Null safety, val and immutable data classes, sealed types and exhaustive when, extension functions, lambdas and the scope functions, and exceptions as the error model. With the models of a real ordering app as the running example.