When engineering managers ask for a cybersecurity code audit, they often point first at a new customer portal or payment widget. Those surfaces matter, yet the quieter authentication and session layers decide whether a flaw becomes account takeover.
Our reviewers start with identity: how credentials are checked, how sessions are bound, how privilege elevations are gated, and where tokens are stored. Only after that map is clear do we fan out into feature handlers that assume the caller is already trusted.
Teams in Taiwan shipping to regional partners sometimes split auth across a legacy monolith and a newer API gateway. That split is exactly where inconsistent cookie flags, missing audience checks, or duplicated role tables appear. Naming those seams early shortens the rest of the review.
If your next release hinges on a new feature, still budget time for the identity path that guards it. The finding that blocks ship day is rarely the button label — it is usually who can press the button.