Kernelbench Agent
Can we get AI to optimize kernels agentically?
Writings on my projects and cool language features.
2025
Reading materials
What does Jack read?
Road to petaflop
It says "3352 AI TOPS" on the tin, can we actually get there?
Claude Code
I try out claude code. It's pretty good!
Trying to change Cursor settings without clicking? Sync them? Read them? Good luck!
No more nice editable json for settings, the AI world demands (checks notes) a JSON blob shoved in a cell in an SQL table 🤦
Mastering Cursor's Agent Mode: Test-Driven Development with AI
An in-depth guide to leveraging Cursor's Agent Mode for test-driven development, with powerful workflows that maximize AI assistance without sacrificing code quality.
Using Cursor AI IDE Like a Pro: Advanced Strategies for AI-Assisted Development
A comprehensive guide to getting the most out of Cursor and other AI-assisted development environments with practical workflows and hidden features.
DeepSeek R1 released: A Leap Forward in AI Reasoning
A stunningly-good CoT model, with even better distilled children.
2024
A quick trial of claude's new computer use
A quick trial of Claude's new computer use feature.
AI Ramp
My thoughts after working on AI for a few months
Narrowing types with asserts
How to make an Optional<T> into T when we're sure
Some tools I found useful
A detailed look into Jack's personal workflow and productivity tools.
Typescript-conforming outputs with Ollama
"Hey please generate a json with these fields" never ever works. Can we do better?
Not all apps are born with a tap
No test facilities? Edge cases that are hard to reproduce but most apps run into? Just another day on Apple's wild ride.
Xcode test lag
Compiled Docc + Blocking file calls = 🤮
Making a binary size viewer
I like Bloaty! I also like cool treemaps. What if I could combine the two?
2023
The case against uFeature architectures
uFeatures offer lower compile times, better modularity, better testability, stronger isolation, and more! Why wouldn't I use them?
Choosing iOS project managers
SPM modules are laggy and stuff. Are there better options?
Trying to improve fatalError
It would be nice to catch fatal assertions, and magically turn all functions into throwing functions. Is it possible?
Fixing uFeature app binary sizes
Porting an app to a uFeature architecture leads to a doubling in binary size. Why? How can we fix it?
Realtime audio processing in AVComposition in Swift
Trying to make realtime and offline cool audio effects without ffmpeg on iOS. Did someone say undocumented C APIs? I wish they didn't!
App thinning 🦙 on iOS
What if you want an app with different downloaded weights for different devices?
🦙 on iOS
I never ended up writing up the stable diffusion port and immensely regretted it, so this time y'alls get to hear about this odyssey of a port.
Fixing llama 2
I wanna use llama, but it doesn't work on Apple Silicon! Can we fix it?
Test closure once semantics in Swift
Trying to get those nice JS testing semantics in Swift
TCA test recording
If you record all of the actions in an app, assert all of the states at every step, and record all of the side effects, you can replay the recording in a test and verify that the app behaves the same way and investigate why. This is a post about how I built a test recorder for TCA.
Laggy SPM refresh
A post for my wandering mind during the couple frozen minutes after any file change in Xcode.
Non-equatable void
A workaround for non-nominal types that don’t conform to Equatable, but really should
Dylib Swizzling
When you want to inject a normal C function, things get tricky
Edit bars
Hard to non-destructive trim!
The meaning of the word "Speaker"
The alternative to 'Speaker' is, apparently, 'Receiver'.
2022
Debugging a spurious AVPlayer KVO Crash
Maybe, one day, Apple will switch to using Swift and we'll see a reduction in SDK bugs.
Copilot outtakes
The curse of dimensionality meets (ai generated:) the curse of copilot
Unfixable edge cases in using Objective-C protocols in Swift
Using runtime declarations as a feature in an otherwise strongly-typed language is not a great idea.
A first look at the Swift macro system
Hopefully this is the beginning of the end of writing Python scripts in Swift code.
SPM metal includes flag
A -> B -> C, but a metal file in B needs to include something from A?
TCA State Sharing
A used in B used in C, but A relies on state owned by C.
2021
Victoria 2 Savegame Analyzer
An abandoned attempt to analyze Victoria 2 savegames and do cool website stuff with it. Perhaps I'll pick it up later?