The whole process was over and done with within 4 days of applying, though both organisation and communication were extremely poor from their end. E.g. I was emailed on the morning of my final interview to inform me that I needed to prepare a presentation, only to be told on arrival that I didn't actually need to deliver it.
They also changed their minds several times about which tests needed to be completed and when, making it difficult for me to effectively manage my time (which was particularly important given the fast pace they wanted to move at).
The process consisted of:
1) Initial phone conversation
2) Excel test (completed at home)
3) Excel test (completed at HelloFresh office)
4) Final interview