Local law is the most common reasons although there is also non-local law such as US sanctions and other reasons.

For a complete list see https://about.gitlab.com/jobs/faq/#country-hiring-guidelines

How come you're not able to hire in some countries in the EU? Sweden, Italy, Spain, and France are on the blacklist.

A Spanish citizen can work for a company registered in any other EU country without any problems.

This probably has to do with local regulations. For example (this might be part of our reasons to hire there) in Spain all employees now have to clock in and out https://elpais.com/elpais/2019/05/13/inenglish/1557739540_96...

There are 28 States operating their own legal systems in the EU and each is free to pass (and does pass!) its own employment and business related legislation albeit within some boundaries of EU law. While I can’t answer this question, it’s not that big of a shock there might be legal issues.

The EU’s “Freedom of Movement” alone does not guarantee a business a right to employ individuals in all 28 States, even if it does greatly help in removing some barriers and permits you as an EU citizen to work In any of them. Any of these states can place additional legal burdens on Gitlab as the employer that it may not be able to meet in its current form, which is presumably what has happened.