Applying for jobs abroad

How do people look up jobs abroad? I see openings in companies like Uber, samsung etc across Amsterdam, Hong Kong. How do we figure whether they are okay with visa sponsorships etc? I haven’t actively sought a switch yet, but wanted to understand how to start looking for such opportunities, what are the factors one must consider. Of course networking is a primary starting point I could think of, but response rate is often low and the answers are also biased