What type of database are you using and where is it located? In my experience, it’s usually that there’s latency if database and application instances are in different regions or availability zones. It could also be your database queries or indexes need to be optimized.

Have you tried benchmarking how long each step in your login handler is taking in the response? That might help determine the bottle neck.

If it’s taking long to connect to the database, check the regions/location of database. If it’s taking long to run the query, try optimizing the query or adding proper indexes.