[srer]

I find interviewing skills are more important than job skills in terms of income.

Trying to get a 20% raise by doing a good job I've found to be a protracted difficult task, but a 50% raise by interviewing? Much easier.

You do need some job skills, but in my experience being fired for not being good enough is rare, and can take a lot of time - during which you're getting paid.

Another thing I've found is I pick up the most exposure to new ideas in that first 12 months in a job.

These two things together means being able to get a new job easily is very useful.

But getting a job is different from doing a job, don't expect the two activities to have much in common. It could be better, but hey 3-4 months of evenings spent programming to get a big step up in the job market is a pretty good deal if you enjoy programming :)

(Personally I've found leetcode useful at becoming a better programmer, though I didn't approach it as memorizing riddles.)