Copy on writes are a big problem in large Python application that rely on multiple processes sharing the same memory. I just sent out a patch introduces Immortal Instances which allows the user to bypass reference counting on specific objects to avoid CoW on forked processes. This has helped in reducing the memory constraints in some of our applications. The PR has a more in-depth explanation about the change. Looking forward to get your thoughts. Github PR: https://github.com/python/cpython/pull/19474 Bug Report: https://bugs.python.org/issue40255 - Eddie E.