monorepo javasript/python ci/cd set up

need a monorepo configured with following constraints -mono repo that will contain multiple projects js/python and can easily share code between them -constraints give permission to access specific part of the project to developer. (not mandatory) easy local development with staging/test/prod env ci/cd find solution that is cheap/cost efficient to bootstrap multiple projects and can scale relatively well imagine following scenario: --generic services auth serverless service in nodejs permission serverless service written in python backup serverless service in nodejs background serverless function service written in python applications : appA is web app using react - appB is mobile app using react native - appC is a web app using remix appA uses auth and permission serverless service appB uses auth and backupp serverless service appC use permission and backup serverless service ci/cd should be configured this way only deploy/rebuild what was changed and depending on the branch name it will be deployed on prod/staging/test master or main is for prod any branch prefixed with stagging is for stagging any branch prefixed with test is for test imagine we only changed code for a pytnon serverless service then only rebuild this service no need to rebuild all keep in mind FOLLOWING REQUIREMENTS: it should be easy to share code between project it should avoid any kind of cloud vendor lock in and should be easy to switch it should be very cost efficient this monorepo can contain javascript and python code as you saw it should be easy to add new application with new domain name it should be easy to develop and test locally. everything is in containers here is an example: [login to view URL] but it is only for javascript and is locked in with aws + lack ci/cd i dont care to use any kind of service as long as they are really cost efficient and it makes sense, avoid them otherwise. do not apply if no experience in monorepo ci/cd and cloud