Do you know what stops Microsoft from building an office in, say, Czechia, hiring all the same people who were previously able to get a US work visa/green card/etc. but are now unable to, for the same labour, and paying Czech rates rather than US rates?

Nothing. Nothing, past tense, stopped them: they already have an office there.

Outsourcing happens but larger firms repeatedly run into the issue that management, admin, and local talent provides diminishing returns. Most of the larger US-based firms have standards that are built on decades of developed industry practices, something that can sometimes be missing from outsourced workforces on a cultural level. Hiring in domestically at least plants folks in environments where they can learn those processes over time. I suspect this is one (amongst many) reasons why US work visas are so single-employer contingent - you don't want talent you trained from the ground up to be able to easily leave for another role somewhere.

That’s not outsourcing. It’s off-shoring, which is (IMO) quite a bit easier and something that a lot of companies are fairly successful at.

Outsourcing is not new, yet they haven't done it to date. you cannot seriously think that visa are the only reason why they didn't to date, or do you?

> Outsourcing is not new, yet they haven't done it to date

I didn't say "outsourcing", outsourcing is where you have a different company do the thing (who may or may not be in the same country).

What I am describing is "offshoring" (specifically where it's the same company, though this is not strictly necessary for the word "offshoring").

> yet they haven't done it to date

  As of June 30, 2026, we employed approximately 223,000 people on a full-time basis, 121,000 in the U.S. and 102,000 internationally. Of the total employees, 89,000 were in operations, including product support and consulting services, datacenter operations, and manufacturing and distribution; 77,000 were in product research and development; 43,000 were in sales and marketing; and 14,000 were in general and administration. Certain employees are subject to collective bargaining agreements.
- SEC filing, MICROSOFT CORPORATION, for the Fiscal Year Ended June 30, 2026, https://www.sec.gov/Archives/edgar/data/789019/0001193125263...

i.e. 45.7% of their staff never even needed a US visa, green card, or HB-1.