During one of the Sylius hackathons I’ve started working on https://github.com/pjedrzejewski/PdosWebhooksPlugin, which allows you to define webhooks via admin panel on certain events. (Like you do on GitHub) I got it to a working state and it was pretty easy. That being said, it needs some testing, updated structure and documentation. If anyone is in need of such functionality - feel free to fork it/rename it. I’d be happy to help with some ideas and/or move the repository.