There should be no hesitation to ping via email. The recipient can respond as quickly as they're able. If they aren't busy that should ideally be within a coupl

There should be no hesitation to ping via email. The recipient can respond as quickly as they're able. If they aren't busy that should ideally be within a couple minutes, and the response given will frequently be of higher quality than an off the cuff answer, since external resources can be consulted. There are many situations in which synchronous feedback won't be possible, wfh or not. For example, when the coworker in question is in a meeting or on vacation. All developers must be able to handle this situation and avoid blockages by switching to another task or an unblocked portion of the same task. The sooner new devs learn to juggle their time and attention in this way, the better.