Key takeaway
A new PM's first two weeks reveal exactly how much of the old system was actually a person, not a tool.
Joining a project as a new PM should mean reading a scope statement, a milestone list, a risk register and a task board, and being reasonably oriented within a day. In practice, on a project run across scattered tools and tribal knowledge, it usually means a first two weeks of meetings whose entire purpose is asking people what is actually going on, because no single artifact answers that question on its own.
Interviewing your way in instead of reading your way in
This distinction matters more than it sounds like it should. Reading your way in means the answers are already written down, consistent, and available whenever you need them again. Interviewing your way in means the answers depend on who you happen to ask, how good their memory is that day, and whether the person who actually knows is even in the room. It is slower, less reliable, and puts the new PM in the position of having to cross-check what one colleague says against what another remembers, on top of learning the project itself.
What a real onboarding artifact looks like
A project a new PM can actually read their way into has a small number of properties: current scope and out-of-scope written down in one place, milestones with real target dates rather than vague phases, risks with owners rather than an abandoned list from kickoff, and tasks that show who owns what right now, not who owned it three reorganizations ago. None of that is exotic. It is just the difference between a project that was documented as it happened and one that was only ever held together by the people who happened to be on it.