Tessa Mero gave a presentation on consuming REST APIs at the MadisonPHP Conference on October 1st, 2016. She discussed what APIs are and how they allow communication between software applications. She demonstrated making requests to the Cisco Spark and Tropo APIs, showing how to get data, create resources, and interact with phones through their API documentation and tools like Postman. The presentation highlighted the importance of APIs and encouraged attendees to experiment with APIs.