Recruiter screen, take-home task, technical screen, behavioural interview.
The take-home task was long, the basic problems can be solved in 3-5 hours, but doing only this will definitely not get you moving to the next stage. So you have to spend at least 8-12 hours on this.
During the tech stage, they discuss the task and your solution and ask questions about things like indexes and concurrency.
The cultural interview will focus on your strengths and weaknesses. If you are honest about this, you will be rejected. You need to make your weakness sound like strengths to succeed here, so you have to lie or you should mention something silly.
Communication from the recruiter was good throughout.
Due to the amount of time required to make it through the process, especially for the take-home task I would STRONGLY ADVISE AGAINST interviewing here unless you have time to burn.
If you check LinkedIn, you can see that most of their engineers are in India and Latin America, so if you are looking for a European salary, you are up against thousands of underpaid competitors from these countries.