PaaS - bobbae/gcp GitHub Wiki
Platform as a service (PaaS) is a cloud computing model where a third-party provider delivers hardware and software tools to users over the internet.
SaaS, IaaS, PaaS
https://www.bmc.com/blogs/saas-vs-paas-vs-iaas-whats-the-difference-and-how-to-choose/
Difference between IaaS SaaS PaaS CaaS FaaS
XaaS
https://diginomica.com/quarter-century-saas-25-years-xaas
PaaS alternatives
https://github.com/bobbae/gcp/wiki/Firebase#paas
Heroku alternatives
https://blog.back4app.com/heroku-alternatives/