Modern enterprise and academic IT environments demand robust, scalable, and secure identity management. However, navigating the rapidly evolving Authentication and Authorization Infrastructure (AAI) landscape can be overwhelming. This conceptual, low-code presentation delivers a comprehensive architectural guide to modern identity and access frameworks from an architect perspective. We will trace the evolution of the AAA system (from HTTP-Basic, LDAP, and SAML to modern OIDC, OAuth2, and OID4VP) and evaluate the shifting paradigms of both identity verification and access control, including group memberships and entitlements. The session covers key concepts like Federated Identity (eduGAIN, SAML/OpenID Federation) and cloud/on-premise IdPs like Shibboleth and Keycloak, alongside current regulatory and governmental standards such as BundID, EU Login, and eIDAS 2.0. Additionally, we will contrast MFA security, evaluating modern MFA approaches like OTP, Passkeys, and EUDI Wallet PIDs. For each strategy, we will weigh the architectural pros and cons while highlighting existing integration pathways within the Python, FastAPI, and Plone ecosystems. Designed for architects, decision-makers, and developers, this session provides the strategic insights needed to build future-proof, compliant identity setups