I can vouch for Odoo and its Builder module. Odoo itself is open source, but there's a paid support model. We implemented an open source version for one of my clients and for business/production/inventory/accounting I'd say it's second to none. The free modules cover maybe 90% of common business cases, and the 10% left can be handled by duplicating one of the free modules and customizing it in Builder. Odoo is actively updated by large team in Belgium if I remember correctly, and their paid support is quite good. Odoo is Python atop Postgres, and uses a simple HTML/CSS/js for the frontend. Quite customizable, and can be a no-code solution if one uses Builder, which covers most use cases.