After 3 years residing on Google Cloud, we decided to move to AWS. GC is generally OK, however, there is some issue related to the architecture of the previous one that may hinder the future scalability!
As such, we decided to re-architecture the site and its workload for the future. There may be some issues after the migration. However, we will check and fix any issue asap.
Refer to the following for the new architecture of the website:
The whole infrastructure was deployed using CloudFormation. The slowest process could be the DNS propagation that took around 10h for the global update.