E.ON Backend Developer interview questions

The first call was a technical call with one of the tech lead and it was overall fine. Then there was a coding challenge that's going to take you between 5 to 10 hours. The second stage was presenting the coding challenge. After spending several hours spanning several days to complete the take-home, I was only allowed 5 minutes to present my solution and was voted down based on that. Everything after that was time wasting.