Sam Tardif, a developer at Atlassian, gave a presentation about building applications using Bitbucket's REST API. He demonstrated how to retrieve issues, branches, changesets, and other repository data to build features like a card wall and issue tracker. Tardif also discussed authentication using OAuth and building apps with frameworks like Flask and Sinatra that interface with Bitbucket's API. He envisioned apps integrated directly into Bitbucket through custom tabs and remote iframes.