It's a little hard to answer the question without knowing more about the product and the rest of the tech stack. But some options are Auth0, Okta, Google Identify Platform, Oauth.io are all worth looking into
@husseinyahfoufi Thank you! Will look into these. We are a content/entertainment site, so we don't need any features beyond login/signup with Facebook, Google etc. Looking for the easiest solution to get it up and running quickly for testing. The site uses React frontend with mostly Spring boot backend on AWS infrastructure.
One thing I wish I had thought of before I went through the user management exercise is where I want my future users to come from. For me it's enterprise, probably active directory, hence I went the azure route after I went the in-house route.
It depends on your target audience. For most people, google and facebook will do the job. These are the most popular platforms and majority of people is likely to use at least one of them. Additionally, you can also use Auth0 or firebase.