The only way this makes sense to me is if they have to contend with lots of expensive parsing, event sequencing, and throttling requirements. Payment APIs, bank websites, etc can be quite byzantine. I could understand how one might code yourself into a corner with a monolithic node app and basically just say "F-it, we're doing this synchronously!"
I don't even think it's a terribly bad thing to do assuming it favors feature velocity.... but at that point, I'd recommend moving away from Node towards something like Python. And if you wanted to dip your toes back into async plumbing land, explore Go or Elixir.
I'd recommend moving away from Node...
Taking a wild guess: Some of their bank integrations probably require browser automation. If you're doing browser automation, the best tool for the job is (currently) Puppeteer, which runs on Node. There are other third-party language bindings for the Chrome dev tools protocol, but Puppeteer is developed by Google as a first-class citizen alongside Chrome.
It's really just bindings for the dev tools protocol.
Half the GitHub issues result in "well the protocol requires X and we can't change that".
Pupeteer is popular because it's web automation protocol bindings for a web language, not because it a sophisticated layer or does very much.
There are literally dozens of language bindings for the protocol. [1] Some are quite good and widely used, for example chromedp (Go bindings). [2]
[1] https://github.com/ChromeDevTools/awesome-chrome-devtools#pr...