How to find outsource developer abroad?

Could you provide me any help, how to find some outsourcing help for programming tasks, as I have never tried this kind before. Mainly, I think, it's going to be Vue / JavaScript, where I could outsource a component that I implement myself - in that way I don't need to open up for the whole codebase and our company critical infrastructure.

I would like to hear some experiences you have about what to do or not to do. I'm in Vietnam and Cambodia quiet often already for vacation, maye 3-4 times a year so this area could maybe be a good option as it would give a better oportunity to meet in person sometimes.

I don't believe price cutting anyone would pay off at the end? So I think it's best to offer a fair hourly price according to the persons residing country to keep that person motivated and my own morale intact. That also means, as we are a small company, that countries with a lower price index are more realistic.

The tasks would be whenever it's necessary to get some work off my hands, so nothing guarenteed. Is it better to find an agency that finds a person everytime, use a site like Freelancer.com, an agency that finds 1 person that I can continue with or find a freelancer independent from any agency?