Hey Ritchie. Re legacy I'm thinking about wider teams in large organisations (eg SWEng system support teams) and IT mandating library upgrade frequency - switching to new libraries can have widespread impacts and the cost can be high. Polars (and Vaex) are definitely here to stay, but I think integration to existing teams may take a while. I followed the PRs around numpy data sharing but I wasn't sure on the end result. Is the data sharing copy-free (always?)? I wasn't sure what the impact was if Rust and NumPy are utilising the same bytes (or even if that was possible). Can you share some detail? Edit - reading the updated thread I your reply https://news.ycombinator.com/item?id=34298023 which says "1D often no copy", can you add any colour to when a 1D no copy can't happen and whether 2D no copy is an option?