This presentation was recorded at Voxxed Days Belgrade 2016 - https://belgrade.voxxeddays.com/ Microservices are the preferred architectural choice for scalable systems, in the recent years. With distributed nature of microservices and REST API being the most prevalent inter-service interface, we are faced with some challenges in choosing the right approach to authentication and authorization mechanisms. We will look into most popular SSO mechanisms, like SAML2, OAuth2 and JWT. We will look into pros and cons of these choices.