How to Implement Identity and Access Management for Multi-Cloud Environments?

First off, it helps to clarify your use case—do you really need more reliability than what the major providers, like AWS, Azure, or Google, offer? Multi-cloud setups can get complicated, especially if you're striving for high availability. Often, fading elements like performance and cost get sacrificed when trying for multi-cloud fault tolerance. Most SaaS options don't truly span multiple clouds in a functional manner; they typically just allow for cloud selection rather than actual multi-cloud operations. If you seriously doubt these vendor's reliability, hosting your solution might be the way to go.

If you're keen on having full control, Keycloak is definitely the way to go! You can set it up across different cloud providers and keep everything running even if one goes down. Plus, it’s free and supports essential protocols like OIDC and OAuth. Auth0, while easier to set up, could introduce a new dependency on their uptime, which seems to contradict your original goal. For true multi-cloud resilience, consider running Keycloak on two providers with a shared database. It can be tricky to set up, but once it’s up, it’s very reliable!

Auth0 does offer multi-region support and is built on Azure with redundancy in different zones. Competing with their resilience while hosting your own Keycloak can be tough, especially if you're not experienced with managing servers. But it does come down to your specific needs and how much complexity you want to handle for high availability.