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kooi

163 karma · joined July 30, 2026

Research Engineer

Current research Interests: Rust for embedded systems, real time signal processing, control barrier functions for robotic manipulators

meet.hn/city/36.9743626,-122.0294673/Santa-Cruz Socials: - https://sites.google.com/view/david-kooi/ Interests: AI/ML, Books, Cycling, Hacking, Hardware, IoT, Open Source, Philosophy, Programming, Research, Robotics, Science, Space Tech, Writing

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kooi··on GPT-6 Astra
I'd call it interpolation on a high dimensional manifold. Convex hull is too simple a shape.

But yes, metaphorically I think that's right.

kooi··on UW pays $600K to settle lawsuit with CS prof over parody land acknowledgment
The other side of peak woke
kooi··on Reasons robotics is hard
Yes the problem is very hard. Mainly because high DOF generalization is very difficult.

We have self driving cars because what are the control inputs? Pedal, brake, steering wheel. This already took many many years.

Now for a humanoid robot: An action space that is metaphorically Hilbert. (Physically, yes, obviously)

Also, IMO, LLM's can aid the development of robots, but do little beyond a planning, human control interface. Below that it's the domain of control and the solution will be the correct combination of classical, neural, and real time optimization based control.

All the bad-ass biped robots that actually look natural? It's PID controls wrapped with control barrier functions constraining the QPs that are being solved in real time.

But that's annoying to derive per-application. So we'll need neural methods which can be learned (while being constrained by a priori knowledge of dynamics). My hunch is that the Yann LeCunn type of jepa models will be how tasks can be learned.

kooi··on About half of Americans say they spend too much time on their smartphone
Me too
kooi··on AI Can Make You Suck Faster Too
I started manual coding again at least 1 day a week.

Its good for the brain, but man it's really slow.

And the AI results prove it: Over the past couple years I've been able to bring several work projects to completion single handedly.

Our R&D company is now handling more clients and we are returning better outcomes/products faster than before.

So...what to do? Results don't lie.

However I will say LLM's can't write multi threaded double buffers by them selves. Probably because they are so application specific.

But I think the reason I can go do fast is because I went so slow before. I have an intuition I can transfer into an LLM. Question is if that intuition will become sloppy as time goes on...

kooi··on Pivotal CEO left the eVTOL company
I used to work there. The product is legit with a well established production line. Hundreds of aircraft in supply awaiting validation and testing.

I wonder how much his stock vested in his 4 years. Could be he vested 10%, is happy, now will move on?

kooi··on Dyson CameraJet electric toothbrush
Man marketing really screwed a great engineered product.

4k resolution mouth camera?? That's why we go to a dentist every 6 months because I wouldnt know wtf im looking at.

"Oh there's that canker sore I feel. Huh, at least I can see it"

Bruh, you don't need a camera for gap detection. Just stick an IR sensor, detect change in light. Boom, $0.05.

kooi··on Launch HN: Nori Robotics (YC S26) – A low-cost humanoid robot for development
Poor buddy looks like he's got the shakes
kooi··on The largest electric aircraft just flew [video]
From the video:

Range: 125 miles all electric

       500 miles with hybrid system (electric + conventional turbo prop)
kooi··on Wayne's Tinkering Page
Some high quality electronics projects here.
kooi··on Develop Cross-Platform CLI and GUI Tools with Tcl/Tk
Its because tk does not have a central event loop built in. You can't use modern programming techniques without building up a significant scaffolding to get multiple UI elements updated based on an events generated in various places. It requires an observer pattern + a self defined callback event generation scheme to collect events (singleton pattern).

Sure you can make this module and there are probably things out there, but you need to wire it up yourself before you even get to the application logic.

kooi··on Develop Cross-Platform CLI and GUI Tools with Tcl/Tk
Worked on a NASA ground control system written in Tk. It was a great way to learn about classic design pattern because we had to roll our own event reactors, observers, plugins.

Honestly it feels very outdated compared to the reactive type of GUI's we have today.

Maybe there are some nice wrappers now that help...

I'd give a Rust based version a try. Just compile into a binary for your platform and off you go.

kooi··on Show HN: Yet another minimal and lightweight terminal multiplexer written in Go.
Thank you, I think this may get me back on a terminal based development path.
kooi··on How do I learn robotics in 2026/2027?
Do you have a specific area you are interested in? That helps narrow down your deep dive hole...because there are so many and you can't do everything immediately.
kooi··on The Cost of Cognitive Debt
I think with more agentic code comes the responsibility of more documentation, more architectural understanding.

Perhaps agentic code is the equivalent to a C compiler outputting what previously was the domain of assembly engineers.

kooi··on Global Capital Atlas
Neat. If I'm ever job searching overseas this will be great :)
kooi··on Those of you who are daily driving Linux, what are your other devices?
Termux is great. I have my phone on the same tailnet as my home server. Easy to SSH into it, start codex in terminal, do some work/server adjustments, log out.
kooi··on ESP32 Firmware Development with Docker Sandboxes
Seems a bit over bloated?

We're using Rust with embassy on the esp platform and its quite wonderful.

We have all peripheral modules isolated and have non-peripheral modules compatible with an embassy desktop scheduler and mock peripherals.

Harnesses are good enough now that you can get them in a loop with the actual hardware.

The next step is to hookup a Saleae and have the agent test against actual signals.

kooi··on Show HN: An autonomous AI agent running one project for two months in public
Sad and yet so funny at the same time. "I could not read my own logs..." XD I'm so tempted to pitch in 9 bucks.
kooi··on Can Reddit survive in the AI era?
Let it die ;)
kooi··on Mindlas catches your coding agent drifting before the bad code
Cool? What's the engine?

We like Sentrux because it's based on score generated from syntax tree parser runs.

kooi··on AI Hurtles Ahead
How? What are you smelling?

His article on the AI bubble analysis is pretty water tight. https://www.oaktreecapital.com/insights/memo/is-it-a-bubble

kooi··on How do I permanently disable random Google Photos popup to backup photos? (2024)
Immich + tailscale is great. Setup a little DNS server and now your computer can go to your photos.<lastname>.It's great.

Setting up backups: Ja. Just setup rsync between a couple computers, good to go.

kooi··on Qwen3.8-27B on a single RTX 3090: crash fix, 131K context, 9 myths
What we see is equivalence to 5.6 Luna. A guess: OpenAI anticipated an open weights release on par with Luna and they dropped price dramatically.

Great writeup, cheers.

kooi··on GPT 5.6 Sol is the best "vision" model OpenAI ever released
Agreed, this like asking a chainsaw to carve a wooden spoon. Impressive it can, but definitely not the right tech to scale.

LLM needs to setup an image classifier to use as a tool call.

kooi··on old.reddit.com Now Requires a Login
skill issue /s
kooi··on Show HN: LinXiv v0.4.0; paper manager now using n0's iroh for P2P collaboration
How does this compare to zotero and why would I use it over that?
kooi··on Reddit Will Be Added to the S&P 500
No wonder they have been gating even reddit post reads. Very lame. On the one hand I get it, they don't want LLM's to scrape their stuff.

On the other hand, come on... that's sure one way to loose traffic.

kooi··on Ask HN: Why are TUIs in trend?
Because of the increased supply of managing remote devices.

The tradeoff with limited graphics is more expansive platform support.

For example, we're doing some Layer 2/Layer 1 networking processing on an embedded linux environment. We can have a nice TUI displaying average SNR, various waveforms, connection status. It's great.

Also, when you do lots of work with remote devices, having something like termscp is wonderful for file transfer.

kooi··on A Tale of Dynamic Programming (2022)
Agreed, very cool article.

> I always struggled to understand practical applications.

Me too...and specifically with non-smooth dynamical systems. I always felt some better knowledge or intuition on my part could lead to understanding the practical application.

It's one reason I left academia... wtf this is cool, but wtf is this useful for?

The closest practical application I can fathom in this theoretical realm is optimization. And welp, since that underlies all AI, that's pretty important. Oh and cryptography.

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