Krieger had to interrupt their conversation at one point to reset the servers, because the teenage heartthrob Justin Bieber had posted again, causing them to crash. That was a fun problem to have, Van Damme thought. The designer became Instagram’s ninth employee when his daughter was just a couple days old. Most startups fail, he thought, but at least for now he had a job, redesigning buttons and logos on an app whose creators cared about style.