Trigger integration test workflow by push to different repository

I am trying to do the following:
I have a git repo which contains our System Integration Tests, those tests should be executed whenever a new version of any of our services is deployed.
I searched for custom triggers in the CircleCI doc to do this but havent found anything except for the HTTP API. I think it would be possible by API but this means I would need to configure the API call in each of my services, it would be better to configure a hook once in the integration test CI config.

Is this possible with CircleCI? If its not possible then what are other options for dong this?

Are you doing the deployment using CircleCI? If so, could you not follow the deployment job with another one?

Yes I am doing the deployment with CircleCI but we have multiple components in the system which are independently deployed and each of them is in a git repo which has the circleci config.
This means I would need to touch all the circleci configs of all components and add a new job which triggers the integration test workflow.
I think It would be better if I could add a hook to the integration test workflow which says “whenever the deploy job of any of the components was run then also run this workflow”

Ah, I see, so you don’t want to copy the integration test into each repo or into each CircleCI config. That’s fair enough.

I think your original idea about the CircleCI API is a good one. I understand what you mean about duplication here too - I wonder if Orbs would help? I have not tried them yet, but I believe they are intended to help with modularisation.