First of all, I am sorry to hear that you weren't invited!
That is indeed an interesting situation which is probably relevant for quite a lot of users (especially those doing their doctorate), so I'm happy to give you my perspective on that:
Without knowing more details about your application files, it is quite hard to diagnose what might have been the reasons why you weren't invited.
Still, given your brief description, my hypothesis would be that either your academic or professional experience simply didn't suffice to get invited:
- You mentioned that your academic records would be fine yet I am not absolutely sure if you were always part of the top ~10% from high school to your Bachelor's and/ or Master's.
- Several of my coachees doing their doctorate gave me feedback that it would be especially tricky with McKinsey to be invited since you normally don't to internships during your doctorate, resulting in a skewed professional experience-academic tenure ratio. Moreover, although internships in startups are most times considered equally relevant, it seems like this would be the sole professional experience you gained.
Unfortunately, once rejected, you will need to wait for about 1-1.5 years and gain additional experience to re-apply - so even getting a referral will not get you back into the process. I would, nevertheless, make sure to be referred next time you apply, even if it won't increase chances significantly.
Furthermore, I am, unfortunately, sure that you will not receive an official reply why you weren't invited, even the feedback from other McKinsey employees from the Nordics would simply be opinions.
If you would like to discuss and have reviewed your application files in detail, please feel free to to contact me directly.
I hope this helps,