In addition to maintaining the default implementation of the Python packaging toolchain, the Python Packaging Authority is also responsible for maintaining the interoperability specifications used to define the interactions between those tools.
PyPA interoperability specifications are currently handled as Informational Python Enhancement Proposals in accordance with PEP 1.
Whenever a new PEP is put forward on distutils-sig, any PyPA core reviewer that believes they are suitably experienced to make the final decision on that PEP may offer to serve as the BDFL’s delegate (or “PEP czar”) for that PEP. If their self-nomination is accepted by the other PyPA core reviewers, the lead PyPI maintainer and the lead CPython representative on distutils-sig, then they will have the authority to approve (or reject) that PEP.
The current lead PyPI maintainer is Donald Stufft, while the current lead CPython representative on distutils-sig is Nick Coghlan.