Jay Phelps

Server-Driven UI, compilers, language design, and reactive programming. Shared Client Foundations at @Netflix

[Jay Phelps @jayphelps]

@andrestaltz @kenwheeler

[Jay Phelps @jayphelps]

@BenLesh NEIN!

[Jay Phelps @jayphelps]

What's the German word for "preferring a new line between /** comments and the previous field"?

Kommentarblockvorleerzeilenpräferenz?

[Ben Lesh @BenLesh]

1/ At @ThisDotLabs, I built a Codex Plugin, called Build Web Data Visualization with DevEx Lead @coreyching from OpenAI.

With this plugin, Codex uses image gen to design the app and then implements it really well. See the examples below. Claude can’t do this!🧵

[Jay Phelps @jayphelps]

Before AI, code "grows" naturally, incrementally over time, in complexity to handle edge cases. After, it can (if you care to ask AI) it can start much more complex. And humans aren't ready for it yet.

[Jay Phelps @jayphelps]

My current issue with AI for coding: I ask it to check for edge cases, and it does a good job at findind [most] of the ones I didn't think of initially.

[Jay Phelps @jayphelps]

Why is that a problem? That means that my PR's contain edge case code that is harder to reason than the more simple PR I would otherwise initially introduce. Which means PR reviews become a lot harder to get past.

Humans are used to this work flow: initial PR of a feature introduces simple code. Over time edge cases are discovered and fixed, but incrementally added over time, so humans are better at accepting "well this sucks but yeah it fixes an edge case" vs. a single larger PR that addresses lots of edge cases all upfront.

[Jay Phelps @jayphelps]

@kenwheeler

[Jay Phelps @jayphelps]

@oriSomething Not in plan mode. But also, I love plan mode!!

[Jay Phelps @jayphelps]

Even AI doesn't know how to react to this message

[Jay Phelps @jayphelps]

Of course having robust test coverage was crucial, and it remains to be seen if this is one of those cases where 99.9% of the way is "easy" but the remaining 0.1% takes forever or causes the initiative to fail.

https://t.co/ecgYx4taH6

[Jarred Sumner @jarredsumner]

I have pretty high confidence in it at this point. It passes Bun’s test suite on Linux x64 + arm64 glibc + musl, Windows x64 & arm64, and macOS x64 & arm64. It likely closes about 200 github issues. Still refactoring & simplifying. Still need to write the blog post.

[Jay Phelps @jayphelps]

AI has unlocked things unthinkable before. Bun was ported from Zig to Rust mostly in about a week.

[Jarred Sumner @jarredsumner]

there will be a blog post about this. on what this means for bun, benchmarks, memory usage, maintainability going forward, and also the literal process of doing this (it wasn’t just “claude, rewrite bun in rust. make no mistakes”)

this is a 960,000 LOC rewrite, the code truly works, passing the test suite on Linux and soon other platforms. e2e I started working on this 6 days ago. this would’ve been a massive amount of work by hand.

[Jay Phelps @jayphelps]

I'm never reviewing another PR again. Will just file a claim.

[nico laqua @nico_laqua]

Today, we're excited to launch AI Coverage (insurance for when your AI messes up).

Insurance was built for risks that have existed for decades. AI is creating a new category very quickly.

[Jay Phelps @jayphelps]

@ThePrimeagen

[Ben Lesh @BenLesh]

Really proud to show off the 3D dungeon game I built for @OpenAI using Codex, GPT 5.5 (and 5.4) and new plugins/skills I worked on. This game was created in about 2 work days, including art and audio, etc. This doesn't even show all of the dev tools that are built in.

[Jay Phelps @jayphelps]

@gabegreenberg @AIEMiami

[Jay Phelps @jayphelps]

@getDanArias

[Jay Phelps @jayphelps]

Hey. April ends today. You know what that means?

[Jay Phelps @jayphelps]

@ThePrimeagen

[Jay Phelps @jayphelps]

@whichsteveyp @ryanflorence I mean, you actually can. He didn't clarify whether they'd let you play or not.