Quart, the ASGI version of Flask, also has background tasks, https://quart.palletsprojects.com/en/latest/how_to_guides/ba..., and there is an extension Quart-Tasks, https://github.com/pgjones/quart-tasks, to run them on a schedule. Via

    @tasks.cron("*/5 * * * *")  # every 5 minutes
    async def infrequent_task():
        ...

In addition Hypercorn, https://github.com/pgjones/hypercorn, (a ASGI and WSGI) also does not use gunicorn, having migrated many years ago.