In order to emigrate to either the United States of America or Australia, based on employment, the company, and you, have to prove that you have the required skills and expertise, and that hiring you wouldn't displace someone already in the country and eligible for the same job.
There is a huge difference between jobs for which you're qualified, and jobs for which a foreign-national would be considered for employment.
For that reason, I'd suggest that you review the US employment-based immigration categories, to see what would fit with your situation.
Approximately 140,000 immigrant visas are available each fiscal year for aliens (and their spouses and children) who seek to immigrate based on their job skills. If you have the right combination of skills, education, and/or work experience and are otherwise eligible, you may be able to live permanently in the United States.
Similarly, the Goverment of Australia offers work-based opportunities to allow individuals such as you to live and work there.
Migration to Australia
If you live overseas and you’d like the opportunity to live and work in Australia, the first step is to find out more about the visa options that are available to you. See Work visas for skilled migration visa options.
@mkennedy makes a good point, addressing your question regarding interviews, which can easily be accomplished via Skype or other video-enabled app.
For that matter, candidates, whether in the country or abroad, are often initially interviewed by phone. Should the discussions become serious, there are visa categories which do allow visits for the express purpose of interviewing for positions.