Link to show how good of a portfolio required to get a job?
For designers? Are you a woman as well? This is a serious comment right?
Leverage your payments/banking background and play that up. Pitch yourself as a walking risk-reduction machine.
For designing product?
Yes, assuming you’ve gained more than a hint of experience in those areas and can talk about it. Specialization can be an easier-than-otherwise way in.
Yes, and at least 4 yoe.
Can you link me an example of a portfolio that would be able to land a job?
Search on LinkedIn for any existing designers at FB or Google and checkout their portfolio