Stacked sessions and pull requests in the GitHub Copilot app

I want you to look at this screenshot for a moment from the GitHub Copilot app. It’s a small one, it’s got a lot of icons, and it tells the most glorious story that I’m really excited about. This image is a set of stacked sessions. They’re a series of tasks in the same repository, where each session builds off each other! More on those below, but first, why is this screenshot so magical? We need to go back more than a decade to start. I have this very old repo of mine for a personal app. I first made it ages ago (end of 2014-ish), and it’s done what I want it to do (it’s like a personal “life” dashboard of calendars and smart devices in my home and task management) for all those years. I occasionally do some updates, but those have gotten harder and harder to wrangle. My dependencies had gotten old. Embarrassingly old. I was using React 15 (which was released in 2016), Less for CSS pre-processing, and a version of react-bootstrap from around that time. Yes, you read that right. Bootstrap. This was old. Trying to untangle this absolute mess before AI would have taken me weeks. I had tried and given up before. It’s not the largest app in the world, but it’s juuuust big enough that it would be painful, and the juice was simply not worth the squeeze. …but we do have AI now, and so I fired up the GitHub Copilot app, added the repo, and got started. First step: Could I one-shot this? No. I tried though! This is the prompt that I used in Plan mode: I passed this into Claude Opus 4.8 got a Rubber Duck review from GPT-5.5, and had to do quite a bit of back-and-forth to make decisions. Once I got to a place I was happy with, I hit “go” and let the app go to town on my project to see if it would work! …it didn’t, and it was my fault. Second step: Realizing I had tried this before So, remember when I said I’d “tried and given up before?” Turns out, I actually had an old