I've managed to go through a EM interview (which was very pleasant to have) and was rejected after technical test, unfortunately with no feedback at all.
As much as I respect and understand rejection at any step by any employer, it feels a bit unfair when you dedicate 4 hours of your time to complete a technical test, and all you get back is "You didn't pass the technical test, sorry".
Many things that could have gone wrong in that particular exercise, many not fulfilled expectations and I was just being curious of what I did wrong or what I didn't to that they have expected me to. Nevertheless, even though I've asked twice for feedback, this remained unanswered. Which in turned left me with very unpleasant feeling of the organisation and the process :(