1. It can only be demanded for exceptional circumstances, with justification. "Poor planning or lack of staff are insufficient." [1]
2. It must be compensated with 25% extra salary, or extra holiday (if the employee agrees). An employee cannot waive their right to this.
3. Even then, there is a limit by law on the number of extra hours you can do in a year, [2] says 170 hours per calendar year. Got a big crisis in January? Employer had better start planning ahead so everyone's time budget isn't exhausted by December.
4. Like many countries, Switzerland has an exception for "management". So you don't call your cleaner a "facility manager", the Swiss law specifies this as "management AND earning at least CHF 120'000 a year". [3] For context, according to expatica [4] the OECD calculated the Swiss average wage in 2017 as 62.3K.
I personally think the principle that you cannot be expected to work "all hours that are necessary" unless you're paid around twice the average salary is brilliant and gets rid of a lot of potential abuse of this rule.
[1] https://www.legalexpatgeneva.com/employment-law/contractual-... [2] https://www.ch.ch/en/overtime-and-extra-hours/ [3] https://www.kmu.admin.ch/kmu/en/home/concrete-know-how/perso... [4] https://www.expatica.com/ch/working/employment-law/switzerla...