🇺🇦 Ingvar Stepanyan
@rreverser.com
Sr. Principal Engineer at Cloudflare by day, WebAssembly consultant by night.
You might also know me from my work on OSS tools and libraries (JS / Wasm / Rust) or Wasm DevRel at Google Chrome
📝 https://rreverser.com/
📷 https://instagram.com/rreverser
You might also know me from my work on OSS tools and libraries (JS / Wasm / Rust) or Wasm DevRel at Google Chrome
📝 https://rreverser.com/
📷 https://instagram.com/rreverser
Reduced example of my code similar to where I found it - reversing bits in 8 u64s at the same time: rust.godbolt.org/z/PYjYoxeYz
November 10, 2025 at 1:45 PM
Reduced example of my code similar to where I found it - reversing bits in 8 u64s at the same time: rust.godbolt.org/z/PYjYoxeYz
Ability to see timing per instruction (when choosing sufficiently high hardware counter precision) also doesn't hurt.
November 7, 2025 at 3:44 PM
Ability to see timing per instruction (when choosing sufficiently high hardware counter precision) also doesn't hurt.
Getting there... Not on par with C++ original that uses handwritten SIMD but getting pretty close, and the microarchitecture usage is looking a lot better now.
November 7, 2025 at 3:30 PM
Getting there... Not on par with C++ original that uses handwritten SIMD but getting pretty close, and the microarchitecture usage is looking a lot better now.
Woah, how did I miss that Compiler Explorer allows to add crate dependencies for Rust?! rust.godbolt.org
November 6, 2025 at 2:58 PM
Woah, how did I miss that Compiler Explorer allows to add crate dependencies for Rust?! rust.godbolt.org
Here's what the docs say:
October 31, 2025 at 8:46 PM
Here's what the docs say:
Easily became my favourite profiler over this time.
There is a lot of good stuff in there beyond traditional flamegraphs, but one of the first things that got me hooked in is "microarchitecture usage" stats - easy way to find functions that would benefit most from SIMD and the like.
There is a lot of good stuff in there beyond traditional flamegraphs, but one of the first things that got me hooked in is "microarchitecture usage" stats - easy way to find functions that would benefit most from SIMD and the like.
October 31, 2025 at 6:14 PM
Easily became my favourite profiler over this time.
There is a lot of good stuff in there beyond traditional flamegraphs, but one of the first things that got me hooked in is "microarchitecture usage" stats - easy way to find functions that would benefit most from SIMD and the like.
There is a lot of good stuff in there beyond traditional flamegraphs, but one of the first things that got me hooked in is "microarchitecture usage" stats - easy way to find functions that would benefit most from SIMD and the like.
Of all the misguided uses of AI, several manufacturers now putting hallucinations inside phone cameras and calling it "zoom" pisses me off in particular.
Why would you have a "camera" app that invents stuff that isn't there? It doesn't even look good. Just show me the naturally blurred picture.
Why would you have a "camera" app that invents stuff that isn't there? It doesn't even look good. Just show me the naturally blurred picture.
October 30, 2025 at 9:18 PM
Of all the misguided uses of AI, several manufacturers now putting hallucinations inside phone cameras and calling it "zoom" pisses me off in particular.
Why would you have a "camera" app that invents stuff that isn't there? It doesn't even look good. Just show me the naturally blurred picture.
Why would you have a "camera" app that invents stuff that isn't there? It doesn't even look good. Just show me the naturally blurred picture.
Chrome DevRel parting dinner, barely 3.5 years later than planned. @surma.dev @jakearchibald.com
October 29, 2025 at 9:35 PM
Chrome DevRel parting dinner, barely 3.5 years later than planned. @surma.dev @jakearchibald.com
Caught the comet last night.
October 27, 2025 at 4:07 AM
Caught the comet last night.
Huh just saw that "due to laws in my region" Instagram now offers an option to pay to use it without ads. Is this new?
October 27, 2025 at 12:44 AM
Huh just saw that "due to laws in my region" Instagram now offers an option to pay to use it without ads. Is this new?
Oh well, since I did anyway.
October 24, 2025 at 8:52 PM
Oh well, since I did anyway.
Oh no I forgot to enable the incognito mode before looking up its history.
October 24, 2025 at 8:49 PM
Oh no I forgot to enable the incognito mode before looking up its history.
Security specialists don't want you to know this one weird trick.
October 22, 2025 at 1:20 PM
Security specialists don't want you to know this one weird trick.
Named it appropriately.
October 22, 2025 at 1:18 PM
Named it appropriately.
Adapted for modern times.
(you wouldn't believe how many tweaks it took me to convince LLM to just add two numbers and return the result)
(you wouldn't believe how many tweaks it took me to convince LLM to just add two numbers and return the result)
![> const session = await LanguageModel.create({
expectedOutputs: [
{ type: "text", languages: ["en"] }
]
});
const opts = {
responseConstraint: {
type: 'number'
}
};
async function addNumbers(x, y) {
const text = await session.prompt(${x} + ${y} = (result only), opts);
return JSON.parse(text);
}
<< undefined
> await addNumbers (10, 20)
< 30](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:pkzt5mk76dc3fnd7w7l7veyr/bafkreibfybwaoskqjg3u2monpcxrzludiqum4shpwx7jc23ddbdjdfw76e@jpeg)
October 22, 2025 at 12:41 PM
Adapted for modern times.
(you wouldn't believe how many tweaks it took me to convince LLM to just add two numbers and return the result)
(you wouldn't believe how many tweaks it took me to convince LLM to just add two numbers and return the result)
So glad Google is prioritising images above the fold. So useful.
October 22, 2025 at 1:02 AM
So glad Google is prioritising images above the fold. So useful.
Forgot to attach benchmark result.
October 20, 2025 at 10:01 PM
Forgot to attach benchmark result.
Something that does work a bit faster is something like this - 35% improvement on a chain of 100 std::iter::once elements, but of course, unlike stdlib, this won't handle double-ended iteration.
October 20, 2025 at 10:01 PM
Something that does work a bit faster is something like this - 35% improvement on a chain of 100 std::iter::once elements, but of course, unlike stdlib, this won't handle double-ended iteration.
Sometimes "referenced by" section of a foundational paper is pure gold.
Tomato quality assessment, star maps, battery defects, ... - you'd think all of these topics can't possibly have anything in common, and yet.
Tomato quality assessment, star maps, battery defects, ... - you'd think all of these topics can't possibly have anything in common, and yet.
October 18, 2025 at 1:56 PM
Sometimes "referenced by" section of a foundational paper is pure gold.
Tomato quality assessment, star maps, battery defects, ... - you'd think all of these topics can't possibly have anything in common, and yet.
Tomato quality assessment, star maps, battery defects, ... - you'd think all of these topics can't possibly have anything in common, and yet.
Typical: you're just trying to use a tool, but then you run into an annoying issue it has and instead of ignoring, you just _have_ to go on a side quest to fix it.
At least this was fairly quick (left: release version, right: with my fix).
At least this was fairly quick (left: release version, right: with my fix).
October 15, 2025 at 11:40 PM
Typical: you're just trying to use a tool, but then you run into an annoying issue it has and instead of ignoring, you just _have_ to go on a side quest to fix it.
At least this was fairly quick (left: release version, right: with my fix).
At least this was fairly quick (left: release version, right: with my fix).
50 stars? I agree!
October 15, 2025 at 8:26 PM
50 stars? I agree!