We have a mix of static and dynamic configuration. We started with almost everything defined in the configuration and implemented our control plane only for endpoint discovery service. Over the time we implemented more and more features there (certificates, tls tickets, route and vhost configuration, etc). We decided to write own implementation on control plane - actually the core part is pretty simple and easily expandable.

We have built our own control plane in golang tightly integrated with an existing infrastructure (service discovery, secrets/certificates management, configs delivery, feature gating, and so on).