All checks of facts are during the interview, but university and master certificate copies will be required for the contract signing day, so don't lie about those. Make a good impression. Random heavy tests don't happen and they do not try to stress you up. It is a very friendly company on that term and the policy is to believe you. But they will check your background later, so don't create unnecessary invented items on your CV. Language written tests are not happening either, but they usually invite a person from the company that speaks Spanish, German, French or so, to make a couple questions during the interview in order to test your communication capacity. So at no point say you are C1 if you are B1, or saying you are B2 when you just started A1. You will be caught on live camera. Before the official interview there is a screening call that happens randomly via phone, the idea is to listen you speak for some 15 minutes as lightly as possible about the application and the company, but they are not worried about what you know about the business, the are checking your English skills, so be clear and chatty. If you just answer with "yes" and "nos" they will create a ton more questions to force you speak, and it will just confuse you on the phone. So try to be descriptive and kind. It is a good place to work. Just salaries are below market average nowadays for nearly every position you see. Read about the business materials, and search how to explain what you know about the role.