What the f*? Of course it would have been easier if you had done it sooner. What you lacked was the willpower from decision-makers who had growth of dollar-signs in their eyes.
You've littered this thread with comments explaining how every move you made was based on ROI. That's the kiss of death for architecture concerns, and bizarrely it puts Node.js on the list of runtimes for data/stream processing backends.
No matter how many times you explain how you made these decisions, I can't help getting the feeling you were wearing horse blinders.
Edit: I find it impossible to imagine that nobody on the engineering team ever shouted, Hey look out! We are basically a Web farm for banking-related requests, this is insane! Surely you've heard from those people and they were let go.