Longest I’ve seen in NL is 2 months, and it’s usually one. It’s common to string multiple “temporary” contracts together though.

It still increases switching cost. As a worker with a permanent contract I have to weigh new opportunities against losing that. And it has real impacts! Getting a mortgage is harder on a temp contract (doable in NL, basically impossible in Ireland)

Six months is the default probationary period in Germany, I can't remember ever seeing a job without that.

Temporary contracts are also a thing here, but if there's no objective reason for the contract to be temporary it will end after max. two years. According to Verdi ~1/13 contracts are temporary - not great, but could be much worse.

This seems like companies will struggle to eliminate roles they no longer need if the person filling it has been around more than 2 years.

The two year limit doesn't apply if the company has an objective reason for making the role temporary, e.g. external dependencies.