You are handing over the most personal parts of your career. Here is exactly what happens to them.
Your legal name is written once, at sign-up, and locked. It cannot be edited later, so an account cannot quietly become somebody else's.
Every statement, CV, letter and answer is stored against your account and readable only by you. Access rules are enforced by the database itself, not by the screen you are looking at.
You can require your device's fingerprint or face unlock before your file opens on that device, so a borrowed laptop does not become a borrowed application.
Your drafts are never sold, published, shown to other members, or used to train anything. Community posts are the only thing other members can see, and only what you choose to post.