I had the very same experience as someone who described it in the previous comments: the process is very long (interviews with HR, the hiring manager, other managers, tests, etc.). As I passed every step, they invited me to visit the offices. They asked for references and examples of previous work. Even though they promised me to let me know their answer, they never did. I also asked for feedback but they never answered. I feel like I wasted a lot of time and energy.