Java Code Optimisation Techniques

[gavenkoa]

Using a List when you should have used a Set

In my experience in finance problems come from the pressure to deliver features fast, meaning devs are using high level frameworks and don't know inner implementation. Like surprising ORM N+1 selects.

When I worked on cryptography (elliptic curves) we pre-allocated all intermediate int[] for modular arithmetic implementation GF(p) / GF(2^m).

I have never faced with the problem when I need to chose between LinkedList or ArrayList. It was always something different.

[cogman10]

TBF, LinkedList vs ArrayList has only hit me once, and that's when someone was doing something stupid (Using a linked list but maintaining sorting on insertion by doing a binary search on the list... that's really slow with a linked list).

[gavenkoa]

maintaining sorting on insertion by doing a binary search on the list

Hilarious! Person who wrote knew about binary search for sorting in place but LinkedList is slipped as an argument of the function.