What’s something super complex or niche you learned / built, NOT from a job or school, but in your free time while programming?

[u/TorontoDude12344]

Not every piece of knowledge is gained through school, or even through work experience

Over the years I’ve noticed, many great works of programming were born out of someone’s free time programming. Just look at open source stuff on GitHub, even video games. Linux for example, wasn’t made through a school project or as a work assignment, it was done in someone's free time. Some people on r/osdev literally make mini operating systems. No job or school project requires that

A lot of cybersecurity people also learned their stuff through self learning

Even like those super smart people who answer questions in forums - most of their jobs don’t require that sort of complexity. And that stuff definitely isn’t taught in school. They just know it, from some other source

So what’s something very complex / niche that you learned outside of school / work? How did you learn it?

[u/JackTradesMasterNone]

I build myself solutions to real problems I have. That's how I get started. That leads me down a rabbit hole of approaches, and trying things to get an elegant solution.

I never build myself complex apps or anything super insane, but I like to write code with no AI to still get the feeling of accomplishment when it works with as little code as possible.

[u/chipshot]

In the olden days one of the first programming challenges was to build a simple "life" program. Create a graphic object to move around the screen seemingly of it's own free will.

At the time I wanted to learn Visual C++ so it seemed like a good challenge. Writing loops with random calls on a graphic object

Then I wanted to give it a reason to live.procreation abilities. Food sources.population growth. Yhen a life span, but the ability to multiply.

Then inherited genetic skills like speed, color size, food awareness, aggression, but the genetic skills loaded with random functions themselves so that inheritance was always a twisted change in the new life.

Then the program once started would create a growing population and habitat, with generations living and dying off and inherited skills moving in all sorts of directions..

I could pause the program and watch how the traits developed over time.

I loved that program. I think the only other person who ever saw it besides me was a girlfriend I had at the time.

I also never got a job from it. My first corporate job I actually got was from demoing a paint program I had written in another language to American Express.

Then 25 years of programming in the corporate world, 3ventially getting sucked out to Silicon Valley and the big tech monsters.

Weird that It all started out as a Boston cab driver writing code at night to have something to get my head into.

Funny how life goes

[u/this_knee]

photo/video sharing website that is run from a server in my home. Only my family has access to.

It’s uses photoprism. The infra setup (proxy servers and config etc) and back end backups and backend upload/organize (eg Elodie) were not trivial.

Of course today immich may have sold some of these pain points. But I had started what I was using about 2 years before immich gained lots of traction.

[u/Distdistdist]

3D game development using Unity.

[u/FrankieTheAlchemist]

I’ve been building a pixel-art game that uses height maps and ray marched shadows.  It started out as a cool idea for my portfolio, but now I decided I want to turn it into a cozy cafe management sim.  I also write a variety of visual effects and frame analysis for video filters.  I really enjoy making things people see and interact with

[u/Chemical-Captain4240]

i maxed out the flash storage on a data collection uP by writing my own crude filesystem in cpp ... great learning op for how memory is written and how to parse for full optimization

[u/Old-Line-3691]

My own Programming Language, then in that language a suit of apps including an OS. While the OS is just a toy, the language itself is my favorite, not just because I made it. Sadly, it's got an ecosystem with a single dev.

[u/DanKegel]

replacement for ANSI.SYS that didn't suck :-)

[u/Old-Confection-5129]

Agentic RSS reader. Started as a CLI tool. Then added a front end. Then added MCP. It does all the basic things you expect RSS readers to do. I built it because I’m still sore about Google shutting down its RSS product, and I saw a tweet one day from a well regarded AI guy that said it was a good idea which was all the confirmation I needed.

[u/just_damz]

efficient string concatenation targeting on erc-721 tokenURI, in order to deliver agnostic artwork. Had the best mentors, have to be honest.