You can memory map and store binary, in-memory data (as long as you don't use pointers). So there'll be some overhead serializing (removing pointers) but ime it

You can memory map and store binary, in-memory data (as long as you don't use pointers). So there'll be some overhead serializing (removing pointers) but ime it's not noticeable since most serialization tasks can be done in milliseconds (even if the dataset is Terabytes) whereas most algorithmic tasks are in the order of seconds, minutes or hours.