Hi, We've built Lowdefy [0] for exactly this reason. It it is open-source, low-code and self hosted. On our team we have data analysts and implementation engineers (non-developers) creating apps in Lowdefy. For Lowdefy I would say that the minimum tech expertise required is someone who can learn to write data queries.

We are currently working on SQL support and should have the first SQL connectors out next week. Please give me a shout if we can be of any assistance! gvw [at] lowdefy.com

[0] - https://lowdefy.com