Ask HN: What are you working on? (September 2026)91 points by david927 8 hours ago | hide | past | favorite | 196 comments What are you working on? What have you been curious about lately? help Just started:1) bad apple on my kernel (OS)2) language model + inference engine from scratch3) sketchdaily.net, but you give it your own pinterest board of references instead of the preselected ones they have I have ALOT of free time since quitting my job.0) money-money-money: A sub 15Kb server-less opinionated household budgeting tool [0]. Why? Its made to be extremely compressible, so you can edit your household budget and share back and forth with your partner via short-links or QR codes. The idea is you edit your budget, send the link to other party, they can view or edit and send back to you without a server in the loop. [0]1) slices: An alternative AI-first ADHD-friendly architecture experiment where everything you code is a "slice" with a shared event pool.

A slice is a fully self contained "feature". Slices can only communicate with other slices through a shared event pool. Inspired by small-talk, vertical-slice architecture, and ADHD.

I used slices to build a self-modifying IDE too. [1] [2]2) text compression experiments: I'm experimenting with approaches to compress text in pursuit of the Hutter prize. The idea is to take the entirety of the English Wikipedia, and compress the text as small as possible whilst still being able to reproduce it. [3]3) tiniest maze solving neural network: A write-up work in progress on a maze solver I built with heavy LLM help, managed to get a 14 byte neural network solving 96% of unseen mazes. [4] [5][0] - https://con-dog.github.io/money-money-money[1] - https://github.com/con-dog/slices-demo[2] - https://con-dog.github.io/slices-demo/[3] - http://prize.hutter1.net[4] - https://github.com/con-dog/tiny-neural-network[5] - https://minimio.ai/I've been working on a voxel game engine called Bonsai for ~10 years. Probably the most interesting thing about it at the moment is the editor.

The world, and most things in it, are represented as collections of SDFs. More accurately, they're density fields, but, potato-tomato. Bonsai has undergone a large rewrite over the last couple years that's nearing completion.

A world edit is defined as a bunch of SDF parameters which get projected/rasterized into the voxel grid by a shader on the GPU. One neat thing about SDFs is they've been thoroughly researched and documented by a guy named Inigo Quilez, and they have a lot of nice mathematical properties. For example, you can do a smooth union of arbitrary SDFs to get nice rounded contours where shapes join.

I've written every system from scratch, all the way from the memory allocators and font rasterizer to the collision detector and simulation loop. I even wrote a metaprogramming language as a replacement for C++ templates, which is a whole other story. IIRC the only external dependency is the C runtime library for starting the process and my very occasional use of variadic functions arguments.

For a long time, an explicit non-goal of the project was to ship a game. It sounded insane to me to write an entire 3D engine and then ship a game. As it turns out, I've gotten it to the point where I can actually make a game.

I've got a start on the game systems in a closed-source repo, and hope to have a steam page for it by the end of the year. I'll do some shameless self-promotion and leave some links here for anyone interested in looking at the engine, language code, or some pretty pictures.https://github.com/scallyw4g/bonsaihttps://github.com/scallyw4g/poof I'm buildingan open-source way to fill U.S. immigration forms without fighting clunky PDFs Github: https://github.com/athos2113/fillvisa-os Demo: https://fillvisa.com/demo/US Immigration still relies on outdated XFA PDFs - you can't fill them on your browser. Most immigrants end up printing the form and fill it manually.

So, I converted the PDF forms into smart we...