By Kate Conger, The New York Times Company In 2008, the handful of employees working for Twitter reached an impasse. Some were focused on preparing for a surge of new users to their social media platform. But one developer argued for another approach: Their platform, he said, shouldn’t be a platform at all. Instead, Blaine Cook envisioned Twitter as a backbone for online chatter, one that would allow its users to freely exchange messages with people on other social media platforms instead of locking them into conversations among themselves.