Aleksander Kruszelnicki describes himself as an almost archaeologist, but his career has been less about digging up the past and more about testing ideas against reality. As a former product manager at Delivery Hero, he moved into the data field as a co-founder, collecting what he calls a few battle scars from failed startup ideas along the way.

Today he co-runs leukos, a boutique data analytics agency in Berlin. The business reached its current shape through a pivot: after exploring data stack as a service and validating the idea with real customers, Aleksander and his team shifted to hands-on consulting, a move that taught him where value actually sits in data work, namely in data modeling and solving client problems rather than in infrastructure alone.

Aleksander shares these lessons openly with the data community. He speaks and writes about building a consulting practice in data: validating customers, running effective user interviews, positioning for European clients, and setting rates, from day rates to project pricing.