I was wondering how professional it'd to ask for some feedback when you receive a template-based rejection email? Or it'd be just a waste of time and would look amateur?
It's probably not going to do any great harm, but I suspect you'll just get back another essentially template response along the lines of:
There were many good candidates for this role and we decided to go with a candidate whose skills and experience more closely matched the requirements at this time.
Thank you for your application and we encourage you to apply for further roles at the company in the future.
which doesn't really say anything either. If the company didn't have time/want to give individual feedback, it probably still doesn't.
how professional it'd to ask for some feedback when you receive a template-based rejection email?
Very professional (Also depends on how you ask it)
Or it'd be just a waste of time ?
It is not waster of time since you may actually get feedback. (Though they are not into any obligation to do so as others have pointed out). One of my interviewer in past actually gave a very detailed feedback on why they are not moving forward with my application.
and would look amateur
No you wouldn't look amateur if you politely ask for it.
You might not get it but there is nothing wrong with asking. If I put working into the application, maybe there were code samples for example I would think it only fair that they put in a little work too. Depending on the company or the type of position you may get a no but I do not see a downside. In fact if someone was rejected for a position, willing to take a little criticism and then reapplied some time later after addressing those concerns I would be somewhat impressed.
That said how you go about it is important. Don't nag them, just ask for a little feedback on where your application or skills were weak.
It depends what stage you were at in the hiring process
Don't ask, they will most likely not want to give you feedback and the feedback would only be based off your resume/cover letter.
If you had a behavioral phone screen with a Recruiter, don't ask, you just need to practice your interview skills. If it was a technical phone screen, feel free to reach out for feedback.
Totally acceptable to ask. The most effective approach would be to reach out to your Recruiter directly who can solicit feedback from those you interviewed with. Reaching out to hiring managers directly may not always be perceived positively.
I haven't had any luck getting responses from asking after a rejection, mostly because the majority of jobs either never let me know my status or it's a "no-reply" email address.
What I have had success with is at the end of the interview, while you're still in the Q&A phase, ask them something on the order of "Is there anything that makes you hesitate to hire me?" I didn't come up with it, but it seems to work, as it was suggested on one of those "how to land a job" sites that actually had good suggestions.
Asking this not only gives you feedback, but you can also then rebuttal with experience or skills you may have accidentally missed mentioning previously.
I've had interviewers say that they can't specifically say there's anything, but "in my professional opinion, here's a list of skills to learn to help your career."
Take notes, learn the things (or not depending on your interests), and try to make yourself better for the next interview. Maybe you'll actually impress the interviewer you asked with your willing to change/learn, so they decide to hire you even with your "missing" skills.