I'm looking for advice...

Has anyone experience with the AWS cloud?
I'm arguing with my future company partner about it. He's totally old school but is responsible for the server stuff... He does the backend for a urgently needed webapp and it takes so long (he still works in his old company the next months).

The frontend (my part) is nearly ready. I could work on the backend fulltime, but I would choose AWS Appsync with offline sync etc. First it would be quick and dirty, because it's really urgent.. he wants to do all super perfect...

How can I handle that? I talked to him many times about that, but he always says it should be done right and takes time. but for me, it's to much time. The webapp is relatively small and the work now already takes about 2 or 3 months..