Pretty mcuh every country's immigration system falls into one of the following buckets:
1) Market based. Companies "bid" on foreign workers, either directly by paying for the visa, or indirectly using the worker's wage. Some form of quote exists, and the highest bidders win.
2) Lottery. Set a minimum qualifications, which is pretty lenient, and a quota that is significantly lower than the number of qualified applicants. Use a lottery system to decide who gets in and who doesn't.
3) Central planning. Some government agency decides which professions and industries are most important to the country, and need foreign workers the most. Politics, special interests lobbying and/or government incompetence in judging market needs, all figure prominently.
4) Some government bureaucrat, who reads through your life story, and spends 30 minutes meeting with you, gets to arbitrarily decide who stays and who doesn't.
4 scares the hell out of me. 2 is just stupid. I don't have any trust in the government's ability to effectively conduct 3. 1 is the least of all evils unfortunately.