There is no need to comply with any EU labor laws if you hire developers as contractors or "one person company". Company from US just gets an invoice directly

There is no need to comply with any EU labor laws if you hire developers as contractors or "one person company". Company from US just gets an invoice directly from developer as this is B2B arrangement. The rest is up to that developer if he wants to work 12 hours a day or else. There is also no real "legal way" that they could hire a dev as full time employee if they don't have entity in EU. So there is not much risk, well only that dev might suck, but that is different discussion.