I work for an American company and live in Metro Vancouver. In fact, around half the team lives here.

We own shares in the American company and are paid through a Canadian subsidiary. That compensation scheme avoids burdening the employees with the difficulty of declaring foreign earnings come tax time.

So for the most part it's the same as working for a Canadian company, but the pay is better.

I used to work for a US company as a remote employee (contractor). I'm a canadian citizen, so it will be different if you dont have the right to work here, but for me its pretty easy. You're basically considered self-employeed and have to declare your income. You also have to register for a GST number (you don't have to charge gst, but you do have to report charging $0. Its weird). The tax forms are easy enough you can definitely just print them out and fill out yourself, or hire a tax person to do them for you. (Disclaimer: not an accountant, hire a real one if you want real tax advice).

I have no idea how it works if your not a citizen. In general i think work visas are fairly easy to get if you are a skilled worker like a software engineer, especially coming from a NAFTA country.

Do you have any specific questions? I am a Canadian, living in Canada, working remotely for a bay area company. Non-us based employees at the company are technically contractors where I work. It's pretty easy come tax time. You need to pay the full cpp amount, as opposed to half if you were working for a Canadian company, and I find the tax writeoffs to be quite meager, but I don't have any complaints in general.