I recently had to switch my application from using one DB to another. The new DB provides API driver only in JavaScript but the Node.js, Express backend was written in TypeScript as the previous database provided TypeScript interface drivers.

Now, my dilemma is whether to keep the old TypeScript backend or switch completely to JavaScript. I've read the response beautifully written and explained by @Alluan Haddad Mixing JavaScript and TypeScript in Node.js I had a look at another question and I had a similar response but one of the response mentions it as illegal!! Can I develop Node.js (Express) app in both JavaScript and TypeScript together?

This project is still in development and will be deployed to cloud when ready.

I'd like to know what is the best practice and what I should do ultimately: keep mixed code or switch to JavaScript completely? Kindly help.

Thanks!