Normal practice is to offer the worker the choice of jurisdiction. It may be the system of law with which the parties are most familiar. If no choice of jurisdiction is specified in the contract, then the contract is governed by the law of the country in which the work is generally carried out - in this case, probably Germany. Under the same convention, if one of the two states has better minimum terms and conditions - for example, on maximum working hours, annual holidays, health and safety at work, or discrimination - the fact that the employee has agreed to have his contract governed by the law of the other state does not deprive him of these benefits.
