What is the difference between using collections and arrays of primitives? Consider Arrays with primitives for performance-critical processing by @marcinmoskala 👇 https://kt.academy/article/ek-arrays

While the general point is correct, the statement about the memory is not. The default list implementation - ArrayList uses array under the hood so there is no overhead in memory usage. The problem with performance comes from different source: automatic boxing.

As mentioned in the article in most cases still using of Collections is better choice, But for sure for some performance critical software arrays ma be good choice.

(Heap)ByteBuffers, IntBuffers, etc. are also arrays with benefits. particularly ByteBuffers allow for primitive conversions to and from from unaligned bytes.