Hi, in my react app I use amplify to connect to cognito, appsync, dynamodb and amazon s3. From cognito a lambda was automatically launched as soon as a user registered so that he was also registered on dynamodb. So with this architecture cognito was used to receive tokens and function, but frankly I find self hosted supertokens more useful since it is free. Is there a way to achieve the same result by saving users to dynamodb? Because I saw that when the docker is created you have to use mysql postgres or mongodb as the database, but if I understood correctly it would be the part that then allows you to manage the users right, like cognito user pool? It would therefore be disconnected from the rest of my app's infrastructure, but then would I have to use aws api gateway or even appsync?

We don't support dynamodb for self hosted as of yet.

Can i intercept user sign up to trigger a lambda to save user informations on dynamodb ?

yup! you can