The interview was started with a programming test, and you can use any language or pseudo code. It's more about logic related to applications of glass design and production, also some basic trigonometry. The interviewer is a very experienced director, and very focused on the technical skill test. They would not continue waste their time if your answer of the test can not make them happy. The company environment is open and comfortable. Since they don't have much employees, almost all the developers are working within one big room. There are only free open car parks in their office, and you should be careful not to use the marked of other company's.