Hi there, for high scalability and high availability (HA), I highly suggest a microservices/serverless architecture.
I am a Senior specialist full-stack and microservices/serverless architect/developer with over 20 years of experience, expert with Docker, Kubernetes, and AWS Lambda and Azure Functions (serverless).
For reference below are microservices/serverless projects awarded to / completed by me here in Freelancer:
https://www.freelancer.com/projects/dot-net/Microservices-Design/
https://www.freelancer.com/projects/nodejs/Microservices-AGENCIES/
https://www.freelancer.com/projects/azure/Azure-Custom-Connectors-Logic-Apps.html
Well-versed not only in SQL, but also with LDAP and NoSQL databases: Apache Cassandra, Elasticsearch, MongoDB, Redis, and Firebase.
My ES6+ JavaScript/TypeScript UI stacks are Node.js, Meteor DDP, Nuxt/Quasar/Vue, React, and Angular.
My cloud platforms are AWS, Microsoft Azure, GCP, and Heroku.
Please see my profile:
https://www.freelancer.com/u/chesslover
Thank you.