I have managed the release of a booking appointment web app, as a front-end developer / jack of all trade (I handled the app design, developed the whole front-end app, managed a distant back-end dev, and managed the client myself). The only thing I wasn't doing is back-end development.
It was a challenging project, since the budget and deadline was very tight, and the back-end dev was working remotely and only part-time, which wasn't planned at first.
The application ended up being released on time, and I was proud of it given the many obstacles in our way, and the many hats I had to wear.