Description: An open-source backend in 1 file with realtime database, authentication, file storage and admin dashboard.

Source: https://github.com/pocketbase/pocketbase

Description: The Backend to Build Anything or Everything. Power any project with Directus – an extensible backend toolkit to create and deploy data-rich apps. Start building today.

Description: With Telefunc, you get a simple frontend-backend relationship: it's just a set of remote functions.
Your frontend can directly use any SQL/ORM query to retrieve & mutate data.