Network-First Safeguards

Register interceptions before any navigation or user action; store the promise and await it immediately after the triggering step.
Assert on structured responses (status, body schema, headers) instead of generic waits so failures surface with actionable context.
Capture HAR files or Playwright traces on successful runs—reuse them for deterministic CI playback when upstream services flake.
Prefer edge mocking: stub at service boundaries, never deep within the stack unless risk analysis demands it.
Replace implicit waits with deterministic signals like waitForResponse, disappearance of spinners, or event hooks.

Source: Murat Testing Philosophy, Playwright patterns book, blog on network interception.