> In terms of what issues caused us to move away from parallelism in the first place, it was all the CPU-bound stuff that you might expect: ReDoS-style issues, post-processing arrays in very large edge cases, programmer error, etc.
But these are not parallelism problems. These are single threading problems, which the core problem with Node.js, not parallelism in general. Hence I think the question stands: why did you choose node for this?
It was chosen about 6 years ago when the product was first being developed, so most of us on the engineering team weren't around when the decision was made. The main choice we're making at this point is: what's the impact and ROI of a language migration vs getting Node to work as well as we can?
> what's the impact and ROI of a language migration vs getting Node to work as well as we can?
Hire an architect costs what? Putting the genie back in the bottle was a problem Plaid baked into its early success, which is common with startups hiring engineers with zero architecture knowledge.
In terms of what issues caused us to move away from parallelism in the first place, it was all the CPU-bound stuff that you might expect: ReDoS-style issues, post-processing arrays in very large edge cases, programmer error, etc.