Q. Why not in Typescript?
Q. Why not use modern Javascript classes instead of the legacy syntax?
Q. Where is the dependency injection, interfaces, test harnesses, unit tests and mocks?
A. Maybe later. I'm not sure those have good ROI. The more code you write, the more you have maintain and debug. Less is more. None is best.
I'd probably focus on playwright first. It measures actual quality.
Q. Micro-services, Micro-services, Micro-services.
A. They are just services. Amazon actually invented them and still does them best. Netflix popularized the term micro because they had to divide up a large single application into several components (like Amazon had already done previously, AWS, the infrastructure Netflix runs on).
It had more to do with enabling parallel teams to work independently on seperate code bases, managing seperate deployments (ala AWS services) then anything about the size of the service.
Five developer teams building 60 container micro-service applications are inverting the purpose of the pattern... almost to absurdity. If you are a small team with little chance of becoming a big team: build a simple UI-API application ala AmpStack and stop the madness.