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

During my master's, I took a job in a physics group that works with high pressure time projection chambers for neutrino detection. They have a bunch of simulation and experimental data they wanted to organize and share with colleagues.

I first worked on improving the database (adding indexes, reducing redundancy, etc.). Next, I wrote a Python package to make it easier to interact with the database from the command line and Python, and act as a backend package for a frontend Flask API I wrote to serve the data. Finally, I made a simple website [1] where users can query the data.

It was great because I not only got to help out the people working in the group, but I also contributed to making the data available to other physicists around the world.

[1] https://rwth-aachen.de/gasdb

When the vaccines were first rolled out, my friends and I made a site that showed PA citizens hospitals and pharmacies near them that had covid vaccines available.

Every week, PA would release a spreadsheet of all places that received vaccines and we would call the places listed to see their availability. We ended up scaling the operation to ~200 volunteers.

There wasn't much on the technical side, though. We had an Airtable where volunteers would update records an a next.js site that displayed the date via Airtable API. We found the Airtable embed to be too complicated/ugly and even though wrangling Airtable API was a huge pain, it was worth

Working now at a bigco, the most impactful thing I do these days is in guiding projects away from building the first thing they think will solve a problem. People don't spend much time doing thought experiments of how changes will evolve in the future or with adjacent scopes. After thinking in that mode for a while you realize that there are concepts here that could and should be separated. A small tweak here and there, changing some naming/terminology goes a long way to saving tons of refactoring/cleanup down the road.

If you mean single-handedly, kinda hard to say. I also rewrote chunks of a retail FX app written in Java1/awt -> Java5+/Swing. Right now I'm enjoying using my own HN viewer (hackerer.news). I'd like to make an SQL-oriented library so people don't have to settle for JPQL/Hibernate--started but not done/promoted.

A recent stroke of luck was working on a small team building buy-online-pickup-instore for thousands/millions of merchants, that completed just before the pandemic hit.

I worked on an ad attribution service for a AAA games company and sold my soul in the process. It was neat maintaining a service that had 130m+ hits a day though, never had to deal with scaling like that since. Even neater was it was just two instances in production. Vertical scaling all the way!

Wow. You were the original querySelector. It's funny how you forget that somebody actually sat down and wrote these things into existence at some point. Thanks!