On the thrumming streets of downtown Vancouver, signs of the Seattle region’s growing economic ties to the city are hard to miss. A rectangular glass and steel office building with a large Microsoft sign occupies nearly an entire city block, sitting atop a large Nordstrom store (another Seattle brand).

Microsoft says it invested $120 million in its new offices in Vancouver, which opened in June, and expects to spend $90 million more annually on wages and other operating costs. It plans to employ nearly 750 people in the city.

Microsoft is hiring Canadians for the facility, but the country’s more open immigration policies were an important factor in its investment, Brad Smith, Microsoft’s president, said in an interview. Microsoft and other tech companies have long complained that the United States education system does not produce enough computer science graduates, forcing them to rely on immigrants from India, China and elsewhere.

Foreign workers in the United States can wait about three times as long for a work visa as those in Canada do, the Boston Consulting Group estimates. And the prospect of Donald J. Trump winning the presidency has raised concerns among tech companies, because of the Republican candidate’s comments about further restricting immigration to the United States.

“Right now, there’s just a lot of uncertainty about open immigration,” Mr. Smith said.

Last month, officials and executives from both cities huddled in a Vancouver hotel to discuss how to enable people, ideas and capital to flow more freely between them, as heedless of the international border separating the cities as a pod of orcas swimming in the sea.