Creator of the list here. For some of the companies on the list the label "startup or scaleup" is debatable ofc. But I often find it not to be a clear-cut thing in those cases.

I tried to use a mix of "criteria" such as company age, whether it acts like a startup/scaleup (rapid innovation, invests heavily in growth, needs external funding to get going), whether it's covered intensely by the startup-focused tech media etc.

To me, Klarna ticks those boxes.