I'd urge your to consider the huge time investment with converting a large web application to TS. It cannot be understated how much effort will be put into it.

I'd urge your to consider the huge time investment with converting a large web application to TS. It cannot be understated how much effort will be put into it. Any moderately sized application with take months of human-hours to get completely switched over. You'll be wrestling with third-party libraries with meager documentation on how to use with TS, lots of googling to understand how to get the compiler to not complain, and a new build system that has its own idiosyncrasies.