I'd advocate against using third party services here. In general third party services and healthcare comes with a lot of hurdles and costs which you need to evaluate carefully. Even log data stored on a 3rd party server that might have some PII can be a violation of U.S. law unless they are a contracted BAA following all the same security and legal rules required of healthcare tech.<p>Overall just start with strong security in mind that will meet the U.S. healthcare security rules/laws, even if you aren't in the U.S., the basic principles are just focused around strong security. People can debate the specific methods, but I will argue using almost any third party service has potential problems for you with compliance. Yes, I agree and understand those services specialize around auth usually, and for most companies that is fine and even for some more fringe areas of healthcare that is fine. But take another viewpoint, that is because those companies secure so many disparate third parties their attack surface is huge compared to your own, and a vulnerability at their end may force you to do public disclosures. That alone isn't a sole reason not to use them, but do consider all the factors.<p>Also, in the U.S. you will likely (depending on specific type of product) need to deal with HIPAA and other similar acts (HITECH/TRUST etc). None of these are actually all that complicated if you take them into account early, although going back and adding them later can be a struggle.<p>Basic principles is secure everything, have timed (short interval) token expiration, have a global token expunge, and always err on the side of reauth over pass thru. Also, if you have many backend services, do not rely on a proxy authentication service to pass off requests. Force all services to validate the authentication of each request. Yes this is "expensive" in terms of extra cycles but it minimizes the risk considerably. Lastly, store trace and audit logs of everything you can imagine, all requests.