angular persist data on multi step form

[Rajendra Rama]

I have an angular multi step form(6 or 7 steps) where the user will be able to fill the form once they login.
The User may fill a couple of steps and logout/close browser and come back later
When the user logs back in later on the same or different device, he should be able to continue the form rather than starting from step 1.
whether user is filling the new form or came back to fill the remaining form, on clicking the back button, data of the previous step should be persisted

All the steps information of the form should be stored in aws dynamodb item(single item with all steps information) with a composite key (may be user id and created date).


How can we persist the data between steps? how to store data in memory so data can be persisted?
how to save the form at every step of angular multi step form? Is it really necessary to store data to database at every step?