These long-lived creatures known as the Stitchers are some of the only people alive today that can say that they saw the Exodus with their own eyes. Although in some cases, they might not have those specific eyes anymore, and will have retrofitted them with a replacement from a "donor".
The Stitchmen are ancient beyond the most basic comprehension of the majority of people during the Resurgence, and possess knowledge and technology that most can't even dream of. While the basic archetype of a Stitcher is one of malice and a vampiric nature, some Stitchers still hold true to their original Hippocratic Oath, and will work in conjunction with communities, doing good even as they seek to ensure their own survival. The vast majority have their own crews and their own enclaves, ruling with a paranoia and manipulation; carefully doling out medical care, bio-engineered enhancements, food, and weapons to those who serve their "master" well. Warped by centuries of narcissism, paranoia and ruthless self-interest, rare is the Stitcher who maintains trust for another living being, least of which are those who share their skills and were once their colleagues. The culture that is bred in most Stitchmen communities is very much "do unto others, before they do unto you". Backstabbing, murder, and coups are all fairly common within a culture that is motivated by the quest for everlasting life, and rife with dementia and paranoid tendencies.
the aftermath of the Exodus, in the times where society fell apart, many Stitchmen would prey on those that came to them for medical services. After a few decades of whispered warnings about the medical malpractitioners, their ‘walk-ins’ began to dry up. In those first years, during the 'Push, some of the more notorious elements of the Stitchers would often botch surgeries when there was still an organ donor program, and then place fake names at the top of the recipient list, and then use those organs for their own purposes, for their own use, and to expand their base of power. After the final collapse of the United States, after the Reunification Wars had long ended, and the Dark Times had begun, Stitchers had to rely on pockets of the weak and isolated, not that their was a shortage of lonely wanderers in the post-collapse world.