drewcrawford

Agent harnesses & LLM evals · Rust/WebAssembly · the Apple SDKs AI products ship on · wasm-bindgen contributor · building AI Bot Mafia (

[drewcrawford @drewcrawford]

If you've shipped Rust to a browser lately, you've already shipped my code. Nov 2025–Mar 2026: #4 wasm-bindgen contributor by commits — 16 merged PRs, ~6,100 lines, incl. a test-runner rewrite measured at 478× on the project's Chrome logging benchmark. https://t.co/GktFyhUWAl

[drewcrawford @drewcrawford]

So forget about Liquid Glass
a sec and just look at this “design” that’s not a shipping product

Three different progress bars, two of which are called “preparing for repair”. But different % complete?

Two identical “updates” with same timestamp and msg?

Apple has changed.

[drewcrawford @drewcrawford]

@travgmont Now that is a name I haven't heard in a long time

[drewcrawford @drewcrawford]

I do not recognize my country anymore.

[drewcrawford @drewcrawford]

@gruber apple sports requires iOS 18 b/c it uses new "broadcast" push. One request => many pushes.

[drewcrawford @drewcrawford]

@matt_levine What happens when cramer recommends SJIM, and why is it securities fraud

[drewcrawford @drewcrawford]

@jorgenpt I suspect the new build system uses inodes. That will be tough to maintain across machines.

[drewcrawford @drewcrawford]

@cocoaphony On ARC ellision, usual suspect is dynamically sized types (array, string, indirect enum). Without heap allocations you don't need to ARC them anymore. Can be expensive to copy tho, so it depends on how much of the ARC is "waste"

[drewcrawford @drewcrawford]

@cocoaphony A good hash function is a PRNG that supports random read. So you wouldn't need mutable state (or locks to protect it). Thread N can get the Nth random byte immediately

[James Waldrop @HiveTheory]

Chad, you didn’t prepare for a system design interview, but I have a simple problem: show me the architecture you’d use to publish 50K tweets/s with a power law distribution for fan out. Your biggest user has 50M followers. Once you’re done, you can compare it to Craigslist

[drewcrawford @drewcrawford]

Has Static Typing Gone Too Far?

[drewcrawford @drewcrawford]

@Catfish_Man

[drewcrawford @drewcrawford]

The implementation of list no longer uses UITableView. (81571203)

[drewcrawford @drewcrawford]

@Aella_Girl “Ask a programmer to review ten lines of code, he’ll find ten issues. Ask him to do five hundred lines, and he’ll say it looks good.” - Gene Kim, The DevOps Handbook.

[drewcrawford @drewcrawford]

@ohunt But we can express a program that doesn't count references in Rust. We can't in Swift. You wrestle the compiler either way, but in one case you win, and the other you redo it every few years. A few cycles of that and the difference is clear

[drewcrawford @drewcrawford]

@ohunt In rust you have the specific monsters Arc, Rc, Box, Pin, etc. So on some level you now have 8 problems. On the other hand each one is solvable because it's explicit in the code

[drewcrawford @drewcrawford]

@rmondello last week someone asked me how feature X was secure against attack Y. I told them, “Because Ricky worked on it and they’re one of the very best.“ (we did figure it out a lot later, but the point stands)

[drewcrawford @drewcrawford]

A modest proposal