This document discusses best practices for web authentication essentials. It recommends using slow hashing algorithms like scrypt, Argon2id, PBKDF2, and bcrypt to secure passwords. Bearer tokens should be used instead of server-side sessions to avoid statefulness. Multi-factor authentication methods like SMS codes, TOTP, FIDO, and WebAuthn API are described along with their tradeoffs. OAuth 2.0 flows like authorization code, implicit grant, and refresh tokens are also summarized. The document evaluates options for authentication solutions, including third-party providers, identity-as-a-service, frameworks, and API gateways.