I would separate this into backend and frontend functionality. For the frontend, this is our recommendation: OpenMRS 3.0: A Frontend Framework that enables collaboration and better User Experience - Projects - OpenMRS Wiki
As per our technology radar, OWA is no longer recommended: https://radar.openmrs.org/
And for the backend, you could look at our attempts at Analytics Engine (including ETL and reporting improvement) - Projects - OpenMRS Wiki and Toward a standard approach for change data capture (CDC) for OpenMRS