[odonnellryan]

I've worked in this industry for a bit and had the opposite experience. Most of the slow solutions have been in other languages due to poor design and algo choice. There have been several projects I've been able to rewrite from R to Python where the runtime on a workstation went from days with R to seconds minutes with Python in a tiny tiny VM (like $10 DO box).

Sure maybe a 3 minute task in python that reconciles a few million transactions and builds some very useful projections is too slow for some pipelines, but it worked for my clients.

[kuratkull]

So the R code was pretty bad and your solution was more optimal - that's the only bit of information in here. The point is that rewriting something means you have extra domain knowledge, bottleneck knowledge, etc that you didn't have during the initial write. Tt might have gone the other way too, initial write in Python is too slow, rewrite in R is faster.

[odonnellryan]

Oh yeah, it definitely was - my point wasn't that R is slower than Python. My point is the only time I've encountered "slow apps" in practice was when they were written in a much faster language, and rewriting them in a slower language resulted in really good performance.