To be honest I never had any long-term vision, and still dont have. I just thought that decentralized software in general and Activitypub in particular is very exciting and lets us take power away from corporations like Reddit, Google, Facebook etc.

Biggest technical problem was implementing Activitypub, when I started there was no implementation in Rust yet, and it was very hard to find detailed information how everything is supposed to work. Over the years I had to rewrite the federation code at least 4-5 times, each time making it a bit cleaner.

Biggest nontechnical challenge is dealing with all the people who are suddenly joining and want to contribute, so that it doesnt turn into total chaos. Luckily there are many helpful community members who helped to organize things. Another challenge is with funding, now we dont have as much time to work on the paid NLnet milestones. And its not clear if NLnet will grant us another funding round once this is over. Hopefully the user donations will grow over time so that they can cover our full salaries.