How to judge if SaaS service can be moved to JAMstack?

by Ravi B

I am interested in understanding how does one go about planning a migration of a dynamic SaaS site to a JAMstack based site.
I am aware that smashing magazine has managed this successfully (they are now really fast). However, they are a media house and do not have interactivity that one expects from a modern SaaS site. What parameters would you use to judge such migration?