Quite long ago, I was asked to co-chair a career panel discussion at UW, Foster School of Business. The focus of the discussion was on the topic - "job transition". In particular, my inputs to the audience was under the title "Engineering to PM".
If you are reading the post then you may be looking for a change and I wish you the very best!
The below are my high order bit, hope this helps!
(1) You are ready for your transition job, when you are already doing it in your current job. The key thing is to identify those opportunities within the existing job or other avenues where you can experience what it is to be on your transition job. On the same note, I would say if you are in an interview, where you are trying to convince the interviewer why "the new role or change in role" for more than 1/10th of the interview slot, then that's an interview almost lost already. Although you may start the conversation there, you must quickly get to the topic of how can you change\contribute what you could do if you get the job.
(2) Mentors - Quickly identify the people who can help you and do not limit your search; you will never know from where you will get the next best mentor. And don't stick to just one; you need different perspectives & inputs. Be very methodical about learning from them: go prepared, set agendas, buy them coffee...
(3) Leverage your network - This is an obvious one, but a very important one, so I would like to re-emphasize the point. Before you apply to a given company, search LinkedIn for your alumni & other friends and gather as many insights as possible.
(4) Most importantly, (also) leverage your cohorts - Prepare mock interviews with them. Share the interview tips & tricks ( I hear you, in some cases your cohorts could be your competitors).
(5) This is a general comment I make, doesn't matter if it is a transition job or not - Prepare a list of companies where you want to work. According to me, if you even slightly doubt you are well prepared, you must first choose companies other than your list of preferred companies when it comes to attending interviews.
(6) Try to garner support from the current employer. The easiest thing to do is to change one thing at a time - if you want to change the role, domain, field, and company, all at once, it may be tough. But it is totally doable. Once you gain the trust & credibility of your employer, they want you more than you want them. They will try to help you with your transition, if possible.