This is the whole main challenge of the quantified self movement all over again.

There's a lot of attempts to solve this problems but not much has been found, possibly because the whole setup of ELT processes is a lot of chores (just think about the whole inconsistent formats of data across services). It's like having a second job in data engineering, and I'm not even remotely in the software/data industry! I just like and do coding as a hobby.