I'm a {{role: PM / designer / new engineer}}. Walk me through what happens when a user {{action: e.g. clicks "Export to PDF"}}, from the UI all the way down to the result they see.
Cover each layer:
1. **UI event** — which component, which handler
2. **Network call(s)** — endpoint, payload shape, auth
3. **Server entry** — which route/controller, what it validates
4. **Business logic** — the actual work, with the file paths of the functions involved
5. **Data layer** — what gets read, what gets written, what gets cached
6. **Response path** — what comes back, how the UI updates
7. **Side effects** — emails, webhooks, analytics events, queue jobs
Pitch the explanation at someone in my role — skip what I'd already know, expand what I wouldn't.system-tracingdocumentationonboarding