When learning on my own, I I prefer to learn things that will last decades rather than years or months. Examples: Linux (bash, core utils, containers), CS (algorithms, data structures), compilers, other paradigms (functional, logic, oop), hardware architecture (logic gates, cpu design, assembly), encryption algos, Vim, etc.

Stuff that I think will only last a few years I will learn as needed on the job or at least on the clock.

You will lose the best candidates with an onerous coding challenge.

Our process, which has been heavily influenced by debate on r/experiencedevs on reddit involves a short phone screen, a 30 MINUTE coding challenge, a tech interview consisting of pair programming, and a non-tech interview with management. Very light.

The coding challenge is a FILTER only. It’s not to evaluate who to hire, but instead it’s to filter who not to continue interviewing.

You learn a lot during pair programming in a short period of time, including personality and team fit. We let them drive and we just watch and discuss. The assignment is to fix a bug, and refactor the code the caused the bug.

Zero downtime deployments can get very complex for heavy usage apps, such as blue-green deployment.

We decided to avoid the complexity with some practical workarounds.

• Most deployments happen at 4am. “develop” branch merges deploy at 4am, and “master” branch merges deploy immediately.
• We force browser refresh if the front end detects the back end has had breaking changes. We attempt to re-populate form field values.
• During database migrations, we send 503 with Retry-After header in response to POSTs. Our client code knows to wait for that time and try again. If the time is too long, the user gets a friendly message that it will try again in X seconds. GETs are handled by an available read-replica, if possible.