I’m not British but have been living here over a decade and I still notice how frequently fireworks go off a week leading up to any of the big nights and for a several days after. Other places I’ve been in Europe very much do fireworks on new years eve only, and just a small handful of teenagers might be playing with fireworks a few days early, or playing with the leftovers the next day.

If coordinating with service providers is hard for a firm, I would argue the cost effective answer isn’t “let’s do all this in house”. Many big finance firms fall in this trap of thinking it’s cheaper to build v buy, and that’s how you get everyone building their own worse versions of everything. Whether your firm is good at the markets or kitchens or travel bookings, thinking you can efficiently in-source tech is a huge fallacy.