When we say Elixir may not be suited to do number crunching, we are usually thinking a bit beyond analytics, averages, medians, etc. Because it is not necessarily the mathematical processing that hurts but rather the lack of support for large mutable data structures that would allow us to do implement things like image processing or support vector machines efficiently.

For example, think how you would implement a 100x100 matrix in Elixir and how much copying you would need to do to change a single {x,y} pair using immutable data structures. If you need performance, your best bet is ETS or falling back to C (which is what many languages do anyway).

If you are worried about analytics on something like Mint, Elixir/Phoenix should be fine.

Excellent question. When you use stream, you are typically trading CPU for memory. I.e. it is more computationally expensive but it allows you to work with large or even infinite datasets.

The Elixir code you’ve got isn’t a particularly suitable adaptation, which isn’t particularly that uncommon when folks are getting going. By way of comparison euler/lib/euler_014.exs at master · sorentwo/euler · GitHub runs in ~4.7 seconds on my computer and it doesn’t even have any caching.