> build a mini-app from scratch in just a few hours
It depends on what kind of functionality we're talking about, but this kind of task is exactly what people at my current startup have been assigned at times. It is absolutely possible to build a CRUD web app with reactive UI using modern tools in a few hours.
> This is like asking a Ruby developer to debug PHP as a test of flexibility
Again it depends on what the debugging task is. At every startup I've worked at, it's expected that an engineer is able to jump into a task that they know very little about. Granted it becomes less reasonable the more niche the task, but PHP and Ruby are not particularly far apart in skillsets in the grand scheme of things. I would expect any web engineer to be able to do this.
> Hiring processes should focus on problem-solving, collaboration, and growth in relevant areas
I agree with this. And, hiring should also focus on technical ability which does include working through difficult and unknown problems by oneself.
It depends on what kind of functionality we're talking about, but this kind of task is exactly what people at my current startup have been assigned at times. It is absolutely possible to build a CRUD web app with reactive UI using modern tools in a few hours.
> This is like asking a Ruby developer to debug PHP as a test of flexibility
Again it depends on what the debugging task is. At every startup I've worked at, it's expected that an engineer is able to jump into a task that they know very little about. Granted it becomes less reasonable the more niche the task, but PHP and Ruby are not particularly far apart in skillsets in the grand scheme of things. I would expect any web engineer to be able to do this.
> Hiring processes should focus on problem-solving, collaboration, and growth in relevant areas
I agree with this. And, hiring should also focus on technical ability which does include working through difficult and unknown problems by oneself.