I'm looking at moving from one software development sub-field to another. A lot of the relevant job ads want expertise with a particular language and a particular set of related tools.
I'm confident that my prior experience in similar but not identical languages/tools will allow me to get up to speed quickly. That is, if I was to start working on an existing project using those tools, I believe that I would be able to meaningfully contribute with more or less the same ramp up period anyone would have when starting work on a meaningfully sized project they haven't seen before.
I'm not sure that the hiring managers would have the same impression of how my previous experience with similar languages/tools have prepared me for this type of work. So, my current plan is to create a small side project, using the expected languages/tools, to demonstrate, (and improve) my proficiency. (This would be while continuing with my current paid work.)
My question is, since I think there's a chance that a hiring manager might count my previous experience with the same weight I do, should I apply to some of these jobs now, before the side project is in a state that makes sense to show?
I've read other posts suggesting that it is not completely taboo to re-apply to the same job after some time has passed. But I'm still left wondering if re-applying is something one should plan to do, or if it would be better to wait until later, given that one is not sure how one's experience would be viewed.