Sam Boyer led the Drupal project's migration from CVS to Git, and continues to lead the efforts of the Drupal.org Git Team to expand Git-related features on Drupal.org. To that end, he is also a member of the d.o infrastructure team.
Sam's core contributions were light prior to D8, but he now devotes a fair bit of effort to a scattering of Drupal's lower-level, critical path systems. In contrib, he co-maintain Panels and CTools with merlinofchaos, and leads maintainership of the Version Control API suite of modules.