Free Open-Source JavaScript form builder library with integration for React, Angular, Vue, jQuery, and Knockout that lets you load and run multiple web forms, or build your own self-hosted form management system, retaining all sensitive data on your servers. You have total freedom of choice as to the backend, because any server + database combination is fully compatible.
Why do you think that https://github.com/formium/formik is a good alternative to SurveyJS