Hi Pacters, We are moving from monolithic app to the micro-service, and I felt end-2-end testing is not sustainable. I just got to know this open source project. However, though I understand what pact wanted to enable us (doing away with the dependence toward e2e testing yet maintaining the peace of mind of releasing), I did not fully understand how can a provider team’s code commit and trigger consumers’ contract testing

Welcome! Good move, both on breaking up the monolith, and knowing that e2e testing isn't scalable in the traditional way. I've popped a link in your other ask with regards to some resources that can help you understand how Pact can aid you as a provider, in understanding how your consumers interact with your API 👍

I did not fully understand how can a provider team’s code commit and trigger consumers’ contract testing

it doesn’t, it goes the other way around. The consumer publishes a consumer contract (their needs) and that is checked against the provider - the triggering goes this way.