Obviously I didn't expect development of this mod to go this long, and I also didn't expect it to take this role as the effective successor to RFC proper. *back in the old days voice* Back in the old days, Rhye was still actively developing and releasing patches for RFC, and people making small self-contained modmods that just tweaked a few things according to their personal preference was very common. I had like a small set of pet issues for how I thought RFC could be better, mostly centered around very minor things like civ colours, and wanting to all have BtS civilisations playable in the mod. I made a couple of posts lobbying for them that were all completely ignored (Rhye's community interaction was... limited), so eventually I decided that it couldn't be that hard to do it myself.
It's important to know that at that time I had just started studying CS, never formally learned to code in school, and the idea that I could effectively modify something as complex as a video game seemed completely impossible to me. I still remember the feeling when I had successfully gotten a civ colour to change in the actual game. I had a very reverent attitude toward the code at that time, never daring to mess too much with basically anything that Rhye had written (not to mention the vanilla mechanics) for fear of breaking something I didn't understand, or causing unintended consequences somewhere. Which is a long way away from my current project or erasing every last trace of Rhye authored code. Also, tooling in the community was so much worse at the time. Setting up a compiler was a huge accomplishment (especially to me at the time). And adding a new civilisation was essentially an arcane process that had to be discovered and then gathered from multiple sources, before I took the time to refactor the code to a point where you could do it in less than an hour once you have the assets together. I remember spending days on getting the Byzantines in. Besides implementing my personal wishlist I also incorporated other smallish modmods that I liked, which kind of made DoC the default RFC + extra stuff mod and I think contributed a lot to its early popularity.
There's been this mutually beneficial relationship between this mod and my academic/professional carreer, where modding would often be a way of putting things I've learned into practice and help me grow my skills beyond the often theoretical context of university or the limited applications of what you're working on professionally, and of course my increasing professional experience fed back into what I am able to accomplish here and what my ambitions are. It definitely built my confidence in my own abilities in the beginning and I still usually put it in my CV in some capacity. There are also elements to this that go beyond programming, managing a very large project you are mostly responsible for yourself, planning and prioritisation, maintaining visibility and communication inside the community. And especially I found it very valuable to have a hobby that has such a hugely creative component. I am literally constantly thinking about what could be improved or what I'd like things to be and the ability to gradually make that a reality is very gratifying, and not something most people really have, especially with the direct feedback of people actually interacting with the thing you are making.