The politically correct answer is: You have to do the best you can to set yourself up for the job you want.
If that's a specific location, network in that location as much as possible. If it's some academic niche or some prestigious academic title, network in those circles and be productive academically.
If you're really lucky, you can do nothing and get handed your ideal job. It used to happen a lot--but now not so much. There's too much competition.
If you're lucky and you've set yourself up as best you can for a position, they might have a position for you since they already know you.
If you're unlucky, your connections will run dry and you'll scramble for whatever you can find. There are a lot of positions that get filled by "Oh no! We need someone right away! Who's out there and available to start on short notice?" Most of the graduating residents who still have no job offers in March or April typically pick up something up like this.
There have to be someone around 100 new Rad Oncs graduated every year.
Close to 200 actually.
My honest and not politically correct answer is: I think the "three A's" are the most important thing right now period.
Even academics nowadays is often trying to hire high RVU producing "go-getters" to build satellite positions and steal the volume away from private practices. That describes the vast majority of new "academic" positions in my state. I know several academic institutions that have changed to "eat what you kill" style entirely RVU based compensation models. This means that there's really little difference between academics and private in a lot of markets.
So academic hiring becomes "we need someone who looks academic", i.e. will at least try to enroll on clinical trials and understand research to try to draw in more patients to the academic practice (so they can keep 90% of the revenue you generate), but those positions are still basically 100% clinical. Those positions typically look for someone who is strong on paper, and then select the best "three A" candidate based on the interview. They're not going to give you anything more than 1 "protected" day per week, which is a joke because it's probably not protected anyway. This is fine by them--if you don't grow professionally this will further limit your opportunities to get promoted or acquire competing job offers and cost more or leave for greener pastures in a few years.
The problem for the employer is: unless they know you, they don't know who is going to embody the "three As". So if they already know you and like you, you have a good chance to get hired if they're hiring. If they don't know you, your CV is going to get buried with the hundred plus other CVs that apply for every job that gets posted on the ASTRO career center. Because how can you demonstrate the three A's on a piece of paper? You really can't. So private groups look for whoever they already know and like or who is connected to the area, and try to sort through whoever is actually *connected* vs. who is just making some connection up so that the employee doesn't just bail when the going gets tough. Now whether the going will get tough because it's a bad practice and they're looking to take advantage of someone or the going might get tough for other reasons is a different question. Then you try to demonstrate the "three A's" during your partnership track period and hopefully make partner. Even in positions that aren't partnership track, there's typically a reward system to keep you around if they like you or exploit you or fire you if they don't like you.
One way new grads used to manage this whole situation was to take their chances possibly in a less desired position for awhile, make connections, and then move to a better position. But, ridiculous mandatory state-wide multi-year non-compete agreements and the glut of desperate new grads are making it more and more difficult to use your connections to move into a better position in the area. Leaving the area is more challenging as well, especially without giving up whatever seniority you managed to acquire.
Still, with the flow of new grads every year, it's not too difficult from the employer's standpoint to just take their chances and make sink-or-swim, churn-and-burn, revolving door style practices. It used to be that the worst academic practices just found foreign "fellows" and "instructors", but nowadays even those exploitative positions are increasingly expanding and filling with US grads. From their perspective, the increasingly desperate new grads will stick around for the location or because the job market sucks even if they never are particularly happy or well paid. There are plenty of people out there in that situation.