Ask HN: What is the most impactful thing you've built?

ModernTeacher.com - The platform has helped 1000’s of schools modernize learning away from traditional 1900’s style classrooms to a modern blended approach. It’s not just about technology it’s also about curriculum, classroom layout, adaptive learning per child etc.

Created the first data team in 30yo corporation in 2007-2008 that shifted the company from proprietary to open-source tech.

A cookie store handling over 50B transactions/day for over 1T profiles

The London Olympics realtime (online) video analytics able to handle over 3M streams on 10 servers (physical).

The March Madness realtime online video analytics

The first realtime distributed OLAP cube

Sold then built then launched a financing tech service to a large bank. Bootstrapped :) Never had more than 2 engineers including myself. System is still live.

Contemporary Art Library, a massive non-profit archive of documentation that will organize, preserve and make accessible the art history of our time[1]. How long that will take depends on the extent to which we can learn how to fundraise, but we already have more than 400,000 pieces of media (images, documents and video) documenting exhibitions, performances and other public artist activity from all over the world. If anyone knows any internet-friendly funders that might want to help accelerate our efforts, let me know! [2]

I created the organization, did the design and helped a colleague building the software. We've had more than 4 million visits from 300k+ users (distributed throughout the world, roughly in proportion to the interest in contemporary art in those countries) and continue to grow most months.

[1] https://contemporaryartlibrary.org

[2] forrest -at- contemporaryartlibrary.org

I don't know if this is impactful, but the projecy that reached out to the most people that I can think of is Mil[0]. It is a small stack-based language that I wrote in C as a learning language. I first showcased it on HN, thinking nothing much than to get feedback. It turned out to do decently well in views and reach, even reaching out to the Chinese tech community because someone posted it on a Chinese social website (I forgot the domain name).

Even though Mil's popularity is pretty typical of my other projects, but seeing it going out to other social media is pretty cool.

[0]: https://github.com/HoangTuan110/mil

Chronolapse

Originally was for the windows folks participating in ludum dare (48hr game dev competition) so that we could easily make timelapses of the development process ( and so I didn't have to look up the ffmpeg command line arguments every time). These were interesting because all games had to be made from scratch in the 48 hours but windows didn't have an easy one liner for it like our linux friends. It grew some simple bells and whistles like cropping, picture-in-picture (it could take a screenshot AND a webcam capture at the same time), and adding audio.

It is terribly, terribly dated at this point (it didn't look great when I released it!) but folks still use it and I get emails from time to time (and a pull request upgrading to python 3 just recently!). I think there were like 50k downloads on google code before they shut that down. It's totally open source and I never marketed it or anything so it was fun to see it featured in some books on indie game dev and some random sites like lifehacker.

The best part for me was all the people who found and used it for things I had never dreamed of - I was sent timelapses of sunrises, custom engine builds, PhD research growing bacteria, construction projects, a ton of digital art, a custom arcade cabinet build, and one guy's year long journey making on very detailed, very cool cyberpunk scene.