I applied through an online advert. The first interview was more about culture fit, then a second one, more technical to see if I had experience with C# optimization, the CEO was part of the interview, asking architectural related questions. From there I was put straight into a live project, with a real problem to solve, to optimize a slow running C# application. I was given one week to get acquainted with the large code base and to come out with a solution of my making. Based on the code base I did a report on the architecture of the application and gave some hints like parallelism, more streamline parsing process etc. With a beginning implementation.