With a PoD anytime after 1267 (when the word Hanse appears in a document) postulate a timeline where the towns of the Hanseatic League evolve into a modern state by 21st century standards.
Well, far from postulating a timeline, but I have an idea.
One of setbacks of the Hanseatic League was its reliance on circulation of silver coin in kind. As a result, merchants from Southern and Western Europe knowing letters of credit and such stuff gradually outcompeted Hansa.
Enter Templars, sometimes called 'inventors of modern banking' (probably an exaggeration, but still there's some sense to it). They had connections with Teutonic Order, and when in early XIV century their order was destroyed, some individual members probably fled to the Baltic Region. (there are dozens of myths and conspiracy theories about this, I'll leave this part to Aunt Google)
Now, let's have Templars receive an advance warning, so more of them can come to Baltic shores, bringing at least some remnants of organization with them. From this point, there are lots of opportunities.![]()