First Week Onboarding Document — Junior Software Engineer, FinTech Platform Team The week before a new engineer joins a financial technology team is the week that decides whether they will still be there in six months. This document is not a welcome pack — it is an operational brief, and it should be treated as one. Maya joins the Backend Infrastructure team on Monday the 14th, with her primary mandate in Week 1 being codebase orientation and security compliance onboarding — two non-negotiables in regulated environments that cannot be deferred to Week 2. Her manager, Daniel, has been asked to treat the first morning as a structured intake, not a social event. Maya will spend the first half of Monday in a one-on-one with Daniel reviewing the team's architecture decision records and the three live incidents from Q3 that are most relevant to her assigned service area. This is not optional. Engineers who skip architectural history repeat it, at cost. By Wednesday, Maya will have completed her SOC 2 compliance training, obtained access to all four core repositories, and attended her first sprint planning session as an observer. The goal of observer status in Week 1 is deliberate: it removes the pressure to contribute before she has the context to contribute well. By Friday, she will submit her first pull request — a documentation fix or test improvement chosen by her onboarding buddy — not because the output matters, but because the process of submitting, reviewing, and merging teaches more about team norms than any handbook can. The measure of a successful first week is not whether Maya has shipped a feature. It is whether, on Friday afternoon, she could explain to a stranger what this team does, why it matters, and what she is responsible for. If she can do that, the onboarding worked.