Authentication is not finished when a user enters the correct password. Sessions, recovery, authorization and audit trails determine whether the system remains safe after login.
Authentication answers who the user is. Authorization decides what that user is allowed to do. A system can have excellent login security and still expose data if server-side routes do not check permissions on every sensitive action.
Keep role and permission checks on the server. Hiding a button in the interface improves usability but does not protect the underlying endpoint.
Use secure, HTTP-only cookies for server sessions where appropriate. Regenerate session identifiers after login, expire inactive sessions, invalidate sessions after sensitive account changes and consider device/session management for higher-risk applications.
Password-reset and account-recovery paths are common attack surfaces because they intentionally bypass the normal login path. Use short-lived, single-use tokens and avoid revealing whether an email address exists when that information would create unnecessary risk.
Administrators, finance users and owners usually deserve stronger protection than a low-risk reader account. Add multi-factor authentication where available, log important administrative actions and make it possible to suspend access quickly.
Track sign-ins, permission changes, team invitations, password or provider changes and sensitive data exports. Audit logs should be useful enough to answer who changed what and when without becoming a second database full of unnecessary personal data.