express-openapi-validator VS LoopBack

The build step is where I put all of them together, which is the messy and tricky part. Although not directly related to your question, I also use this validation tool to handle request validation based on my result yml.

express-openapi-validator Express middleware that routes and validates requests according to an OpenAPI spec.

The express-openapi-validator package addresses this issue by validating requests and responses based on a provided OpenAPI spec. Having our responses validated in addition to just the requests will be a good idea as that will ensure the API code always responds in the expected schema.

Backend is usually an API you design, can simply use Rails for this, basic Express.js or some framework like https://loopback.io/ if you want javascript otherwise you want 'system design' https://github.com/donnemartin/system-design-primer for all the load balancers/dbms if that's what you mean.

LoopBack – Highly Extensible Node.js and TypeScript framework

We deliberately decided not to use "kitchen-sink included" frameworks such as Laravel, Django, Loopback or Nest.js to keep things simple.

Loopback

I'd say check out https://loopback.io

This interface defines the basic CRUD capabilities that any entity should provide. This contract is based on frameworks like Loopback, Django RF, RoR and Spring. The Service.kt looks something like: