Why you shouldn't start a job without clear expectations
I believe that most of us, want to be rewarded for our achievements, not for being able to play the system. To maximize your chances, it would be ideal to have a shared understanding with your employer of what success in your role means.
When you start a job, you should know what they are expecting from you, especially during the first couple of months. All too often, this is not clearly communicated, which puts you at risk of being fired for underperforming or having to play of politics to appease the right people.
Having ambiguous expectations gives a lot of power to your boss, as any day, they can change their minds about what they expect from you. You can receive great feedback for months and then, for some reason someone starts to perceive your differently, and all of a sudden that same work won't do.
I hoped you would...
Imagine your boss tells you to focus on topic A, while your team assumes you would pull your weight on B, which you neglect as you've been given different priorities.
If you are lucky, someone might share their views with you in the form of feedback, but even then, you are new, you have no official guidance, so you don't know who to trust.
What makes this pattern even more troubling to me, is that there will be half a dozen people who hoped you would do certain things.
On one side, it's nice that people visualize your success, but it would be even nicer if they ran it past you.
Sooner or later, someone gets mad enough at you for not performing according to their personal expectations, to complain. That can snowball into formal warnings or a quick termination. That tough conversation usually includes "I hoped you would".
Whether you actually get fired or not, you probably don't want to stay in a place where people resent you, so the damage is done.
Set yourself up for success
To avoid getting into this game of Russian roulette, I highly recommend starting during interviews to ask about these topics to gauge what you can expect in your first months:
performance review process and frequency - what are the measures? who picks them? what were the measures related to your role last year / period?
onboarding - do you get a list of onboarding tasks? is there a sign off? is it formal? how long does it take and what does it cover?
are performance goals the driver for salary increases and promotions?
what is the role - is it specific enough? or is it pick your own adventure?
what are the expectations for this role?
what are the expectations for this position? (project / team specific)
What you are looking to avoid is your employer judging you based on: gut feelings, favoritism or through blindly following bureaucracy.
Situations worth avoiding
Unless you want to be the one who puts this in order, keep your eyes open for red flags.
It's easy to look past these topics and assume it will all work out. The problem is that these situations rarely resolve in an amicable way.
When someone is fired a year into a job, because expectations weren't clear, a misunderstanding, that could have been addressed has turned into a very dramatic situation and a lot of time has been wasted on both sides.
I've sat on both chairs in that situation. As a manager, you feel guilty for not addressing the issue during the probation period. As an employee, you are shocked that for so long you misunderstood what was expected of you.
If you can, it's really worth saving yourself that trouble.