Launching the first somewhat useful product that I had worked on very nearly from the ground up, as part of a real team including people who actually knew what

Launching the first somewhat useful product that I had worked on very nearly from the ground up, as part of a real team including people who actually knew what they were doing. In hindsight, my contributions were more trivial and janky than I thought at the time, but nevertheless they were in there, in a non trivial working product. It showed me that it's not magic, it's actually possible to build things and make them work.