To import DB data and expose it to the user's screen

[help_me]

Hello!
I'm a developer using Shopify for the first time, and I ran into a problem regarding a functionality I am developing. I'd appreciate any advice, and thanks in advance!
I'm using an app proxy to fetch the backend data for the user's screen. To explain the issue, I'm to create a bulletin board app that loads a list of posts, and I've tried loading the list data using the javascript fetch function. However, utilizing javascript's fetch, exposing the data onto the user's screen takes a noticeable amount of time after accessing the page.
I also tried to print the list data using the Metafield, but this also takes a long time to display the list to the user.
I'd love to resolve this issue and would appreciate any advice or tips to implement a solution.
Thanks again!