For a while now, the kernel's configuration and build systems have been an area of concern for me. Almost nobody truly understands those complex subsystems, which were handled by a single maintainer.
That maintainer, Masahiro Yamada, has just stepped down after eight years on the job:
https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8d6841d5cb20Happily, Nathan Chancellor and Nicolas Schier have agreed to pick up the build system. The configuration system, instead, is now unmaintained. That ... seems less than optimal.
Thanks to Masahiro for doing this work all these years, and to Nathan and Nicolas for stepping up!