You don't always get a big "aha!" moment when trying to solve a problem, but when you do, it's pretty sweet.

"... image stabilization was the answer, but the technologies of that time, which you’d find in Final Cut and myriad other video editing programs, were simply unworkable for smartphones. ... image stabilization algorithms typically analyze a movie frame by frame, identifying image fragments common to each. By recording how those shared points jump around across frames, algorithms can then infer how the camera has been moving. By reverse engineering that motion data, software can recreate a new, steadier version of a film clip. Yet every step in that process requires processing muscle. That’s fine for a movie studio, which has massive computers that crank overnight to re-render a scene. It’s ridiculous for a smartphone... Karpenko had an aha moment: Smartphones didn’t have nearly enough power to replicate video-editing software, but they did have built-in gyroscopes. On a smartphone, instead of using power-hungry algorithms to model the camera’s movement, he could measure it directly. And he could funnel those measurements through a simpler algorithm that could map one frame to the next...

From an article in Wired about the creation of Hyperlapse for Instagram.