Create Large Form using JSON

Hi … im looking to create a Large Form with about 100+ fields in it. It is a Questionnaire that im looking to create. Building this form in the Drag and Drop interface will be cumbersome. So was wondering if there was an easy way to just include the fields in a json file and build the form using that? Any suggestions for building large form? (Tried searching the forums for similar use-cases but couldnt fine any. Please point me to any resource if available) Thanks in advance! Chris