This might be an unpopular opinion, but I would expect that each newly hired developer (be it junior, mid-level, senior) can and will take time to do train and improve him/herself. I don't mind this being on job time, as long it is not all day. Most times this is even required when doing a task, because no one knows everything, even with X+ years of experience. If this mindset is not there and a newly hired developer…
To me this seems more like "common sense" than an unpopular opinion. As such I hope this isnt an unpopular opinion!
I think in the HN community this is probably common sense.