Worked on hardening class instantiation behavior in the Chimera repository, focusing on enforcing strict safeguards for Python classes lacking a __new__ method. Leveraged the Python C API, specifically Py_TPFLAGS_DISALLOW_INSTANTIATION, to prevent improper instantiation in Python 3.10 and newer, while implementing compatibility workarounds for PyPy environments. Enhanced error messaging to provide clearer developer feedback and updated the test suite to ensure consistent behavior across CPython and PyPy. Utilized both Python and Rust to address cross-platform compatibility and testing requirements. The work addressed a critical bug, improving reliability and predictability of class instantiation logic within the project’s codebase.