Patrick Dubroy
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dubroy.com
Patrick Dubroy
@dubroy.com
1.5K followers 280 following 630 posts
Programmer & researcher, co-creator of https://ohmjs.org. 🇨🇦 🇩🇪 🇪🇺

Co-author of https://wasmgroundup.com — learn Wasm by building a simple compiler in JavaScript.

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dubroy.com
Patrick Dubroy @dubroy.com · Mar 10
Here it is — very happy to officially release the book that @marianoguerra.org and I have been working on for the past 2½ years.

If you bought it in early access, thanks for your support! 🙏

If you haven't bought it yet, please check it out!!
wasmgroundup.com WebAssembly from the Ground Up @wasmgroundup.com · Mar 10
Excited to announce the official launch of our online book, WebAssembly from the Ground Up! 🎉

It's the book we wish we'd had 3 years ago.

No messing with tools and frameworks. It's a hands-on guide to the core of Wasm: the instruction set and module format.

Link below. 👇
Learn Wasm by building a simple compiler in JavaScript. No compiler expertise necessary. All the code is in the book; we'll take you through it step by step. Get your hands dirty and see for yourself what WebAssembly is all about.
dubroy.com
+1, really enjoyed this talk.

Some incredible examples involving the "the sophisticated software at the very lowest layers of the stack".
eatonphil.bsky.social Phil Eaton @eatonphil.bsky.social · 5d
I watch very few technical talks on video (I prefer to read) but found Bryan Cantrill's recent presentation at Jane Street enthralling.

www.youtube.com/watch?v=v0Jj...
Bryan Cantrill: Andreessen’s Folly - The False Dichotomy of Software and Hardware
YouTube video by Jane Street
www.youtube.com
February 5, 2026 at 1:47 PM
dubroy.com
I've been looking at patterns for specific "migration" and "compat" packages in the JS ecosystem.

I know about:
- react-router-dom-v5-compat
- @ vue/compat
- ember-compatibility-helpers
- jQuery Migrate

Any others I should look at? Bonus points if you've used them successfully.
February 5, 2026 at 8:38 AM
dubroy.com
Don't miss this! It's a joy, and it feels like a throwback in the best way possible (caring about UI details, remember that??)
aresluna.org Marcin Wichary @aresluna.org · 17d
I’ve been working on this for a while, but let’s make it official: I started a little Tumblr-like microblog about software craft and quality!

You can sign up via RSS or a weekly newsletter digest. There’s already almost two months of content, if you just want to check it out.

unsung.aresluna.org
Unsung
unsung.aresluna.org
February 5, 2026 at 8:26 AM
dubroy.com
What I'm doing now
→ dubroy.com/now/

Note: I have availability for consulting projects in 2026. If you know of something interesting, please get in touch!
Freshly baked pita breads cooling on a black wire rack on a kitchen counter, with a light blue kitchen towel on the left and fresh parsley on the right. The pitas are puffy and golden-brown with a light dusting of flour on their surfaces.
February 2, 2026 at 1:14 PM
dubroy.com
TIL: HTTP Range requests
→ https://github.com/pdubr...
Did you know that HTTP supports requests for a specific range of bytes? I didn't! I first saw this mentioned a few weeks ago in the Protomaps documentation, and then it came up again in an episode of Developer Voices about DuckDB. MDN: HTTP range requests: An HTTP Range request asks the server to send parts of a resource back to a client. Range requests are useful for various clients, including media players that support random access, data tools that require only part of a large file, and download managers that let users pause and resume a download. Here's an example: curl https://i.imgur.com/z4d4kWk.jpg -i -H "Range: bytes=0-1023" --output - …which issues the following request: GET /z4d4kWk.jpg HTTP/2 Host: i.imgur.com User-Agent: curl/8.7.1 Accept: */* Range: bytes=0-1023 I was kind of surprised that I hadn't heard about this before, but I felt better when I found out that Kris hadn't either :-)
January 31, 2026 at 2:27 PM
dubroy.com
New blog post —

Look for what's true
→ dubroy.com/blog/look-fo...
A few times in my career I’ve gotten feedback that really knocked me on my ass. The first few times it happened, I wasn’t mature enough to learn much from it. But eventually I discovered a little trick — something that helps me set my ego aside and actually listen. The details aren’t all that important, but to set the scene: a Principal Engineer I worked with had called me out for being overly negative in a meeting. He pointed out that, as a senior IC, I should be mindful of how my actions could affect those around me. In hindsight, he was spot on; but in the moment, it felt mostly wrong and totally unfair. I spent the rest of the day in a miserable mood. In the evening, I was still stewing, and considering how to respond. I think I even started drafting a rebuttal email (I know, I know).
January 28, 2026 at 4:03 PM
dubroy.com
TIL: Tidy Data
→ https://github.com/pdubr...
On Friday I took the train from Munich to Brussels, and on the way there, converted my financial planning spreadsheet to a Python script using pandas. Now, on the way back home, I'm reading about siuba and dplyr, and I learned about Hadley Wickham's concept of Tidy Data: Tidy data is a standard way of mapping the meaning of a dataset to its structure. A dataset is messy or tidy depending on how rows, columns and tables are matched up with observations, variables and types. In tidy data: 1. Each variable is a column; each column is a variable. 2. Each observation is a row; each row is an observation. 3. Each value is a cell; each cell is a single value. This is Codd’s 3rd normal form, but with the constraints framed in statistical language, and the focus put on a single dataset rather than the many connected datasets common in relational databases.
January 25, 2026 at 2:40 PM
dubroy.com
For those who might not be aware —

"OpenAI co-founder and president Greg Brockman gave Trump’s super PAC a whopping $25 million" www.sfgate.com/tech/article...

"US Army appoints Palantir, Meta, OpenAI execs as Lt. Colonels"
thegrayzone.com/2025/06/18/p...
January 21, 2026 at 12:56 PM
Reposted by Patrick Dubroy
gfor.rest
Still thinking about worker vs boss mentality about AI.
Little Bosses Everywhere
grant.leaflet.pub
January 19, 2026 at 8:27 PM
dubroy.com
"I have been maintaining my site for over 30 years. It’s older than Wikipedia or Google. Most software doesn’t last that long, and I don’t expect sassc or esbuild to last as long as my web site. When I’m choosing tools I ask myself 'what happens when this software disappears?'"
redblobgames.com Red Blob Games @redblobgames.com · 21d
Blog post from last month: I simplified my web site build process by switching from Sass to nested CSS www.redblobgames.com/blog/2025-12...
Goodbye Sass
www.redblobgames.com
January 19, 2026 at 6:56 PM
dubroy.com
New blog post:

De-Googling
→ dubroy.com/blog/de-goog...

…in which I tell you about some great services & companies that I'm very happy to have discovered.
Since early last year, I’ve been trying to reduce my dependency on the big US tech companies, and US companies in general. Following Tim Bray, I’ve been thinking of this as de-Googling. I don’t really want to get into the reasons, except to say that I’m under no illusion that my support (or lack of it) makes any difference to those companies. For me, it’s much more about reducing risk1, and about supporting smaller companies whose interests are more aligned with mine. Anyways! I wanted write about my progress here, in case it’s useful to anyone else who’s also considering this. (For a more in-depth discussion of the various alternatives, I found European Alternatives and Getting off US tech: a guide to be quite helpful.)
January 16, 2026 at 3:35 PM
dubroy.com
Two talks on data-oriented design that I enjoyed this week:

Data-Oriented Design and C++ by Mike Acton
→ www.youtube.com/watch?v=rX0I...

(End with an unfortunately lame quote, but otherwise great)

Cpu Caches and Why You Care by Scott Meyers
→ www.youtube.com/watch?v=WDIk...
CppCon 2014: Mike Acton "Data-Oriented Design and C++"
YouTube video by CppCon
www.youtube.com
January 10, 2026 at 1:57 PM
dubroy.com
TIL: One-liners for downloading media
→ github.com/pdubroy/til/...
Two little tasks I had this week, which I learned some handy one-liners for — (And I love that these are now one-liners thanks to uvx!) gallery-dl for downloading GIFs from Twitter For my Twitter archive, I wanted to download the original GIFs from a couple of my tweets. I used gallery-dl — uvx gallery-dl 'https://twitter.com/someuser/status/123456789' yt-dlp for downloading YouTube videos Then, I wanted to watch a YouTube video (Cpu Caches and Why You Care by Scott Meyers) and for some reason the player wouldn't let me change the speed. For that I used yt-dlp: uvx yt-dlp 'https://www.youtube.com/watch?v=WDIkqP4JbkE'
January 10, 2026 at 1:44 PM
dubroy.com
Lots of gems here. Definitely worth a read if you blog or would like to.

(And I'll be following @thorstenball.com's advice in 2026: set a schedule.)
cynthiadunlop.bsky.social Cynthia Dunlop @cynthiadunlop.bsky.social · Jan 8
Here's one final remix of the 2025 tech blogger interviews: everyone sharing their top blogging lessons learned writethatblog.substack.com/p/technical-...
A screenshot sharing tech blogging lessons learned from Sam Rose and Phil Eaton
January 9, 2026 at 6:35 PM
dubroy.com
Finally have a self-hosted version of my personal Twitter archive, so I can really, truly delete everything over there.

→ dubroy.com/twitter

It's actually a lot of fun going through these! And orders of magnitude faster and more pleasant than on the official site.
Patrick Dubroy's Twitter Archive page listing tweets by year from 2008-2025. Screenshot of a 'Popular' tweets section showing two posts. The first tweet from May 5, 2017 (3159 likes, 1428 retweets) comments on putting heads on geometric forms to aid mental rotations, with an embedded image of academic text about body-syntonicity in problem solving and the concept of 'kobitos' (little people). The second tweet is titled 'How to get VC funding' and shows a satirical recipe with bullet points about looking at complex realities, failing to understand them, attributing failure to irrationality, and creating an idealized vision.
January 9, 2026 at 11:34 AM
dubroy.com
"Valgrind is in essence a virtual machine using just-in-time compilation techniques."

Huh. I had no idea.

en.wikipedia.org/wiki/Valgrind
Valgrind is in essence a virtual machine using just-in-time compilation techniques, including dynamic recompilation. Nothing from the original program ever gets run directly on the host processor. Instead, Valgrind first translates the program into a temporary, simpler form called intermediate representation (IR), which is a processor-neutral, static single assignment form-based form. After the conversion, a tool (see below) is free to do whatever transformations it would like on the IR, before Valgrind translates the IR back into machine code and lets the host processor run it. Valgrind recompiles binary code to run on host and target (or simulated) CPUs of the same architecture. It also includes a GDB stub to allow debugging of the target program as it runs in Valgrind, with "monitor commands" that allow querying the Valgrind tool for various information. A considerable amount of performance is lost in these transformations (and usually, the code the tool inserts); usually, code run with Valgrind and the "none" tool (which does nothing to the IR) runs at 20% to 25% of the speed of the normal program.[7][8]
January 7, 2026 at 7:06 PM
dubroy.com
TIL: Protomaps and PMTiles
→ github.com/pdubroy/til/...
I spent three years (2018–2020) working on mapping, and haven't followed the space closely since then. So I didn't hear about Protomaps when it was announced a few years ago. But, it looks very useful: Protomaps enables frontend developers to easily "self-host" maps - it's just a file, no server setup required. It makes serving vector map tiles simple and affordable by using HTTP range requests. There are more details in the docs: There are three major parts of Protomaps: PMTiles, an open archive format for pyramids of tile data, accessible via HTTP Range Requests. An ecosystem of tools and libraries for creating, serving and manipulating PMTiles. A cartographic "basemap" showing features in the world like roads, water bodies and labels, based on the OpenStreetMap dataset, and delivered as one big PMTiles archive. (And I must say, my first impression is that the docs are very, very good.)
January 6, 2026 at 3:43 PM
dubroy.com
So much good stuff here!

And lots of it can be applied to many other areas: learning experiences, programming languages, etc.

via @szymonkaliski.com
January 5, 2026 at 9:34 AM
dubroy.com
What I'm doing now
→ dubroy.com/now/
A snowy winter landscape featuring a set of footprints creating a path through a white field. To the left, a tall, textured tree trunk stands near the foreground, while a large, leafless tree on the right is silhouetted against a bright, cloudy sky with the sun peeking through. In the background, a line of dark evergreens meets the horizon.
December 27, 2025 at 3:53 PM
dubroy.com
TIL: V8 Natives syntax
→ github.com/pdubroy/til/...
V8 has a number of built-in, runtime support functions that are written in C++. For debugging purposes, if you run with the --allow-natives-syntax flag, it's possible to call these functions directly from JavaScript with a % prefix. For example: function getTypeTagged(node) { return node.type; } console.log('=== Optimization Status (after warmup) ==='); const taggedStatus = %GetOptimizationStatus(getTypeTagged); console.log(`getTypeTagged status: ${taggedStatus}`); The full list of functions is in src/runtime/runtime.h in the V8 source. Here are a few that I found useful/interesting: %GetOptimizationStatus %HaveSameMap %HasFastProperties
December 24, 2025 at 1:20 AM
Reposted by Patrick Dubroy
burrito.space
fun romp through the Chromium graphics stack from an @electronjs.org dev

www.electronjs.org/blog/tech-ta...
Tech Talk: Improving Window Resize Behavior | Electron
We're launching a new blog post series where we share glimpses into our work on Electron. If you find this work interesting, please consider contributing!
www.electronjs.org
December 21, 2025 at 10:55 AM
Reposted by Patrick Dubroy
wasmgroundup.com
We just sent out our last newsletter of the year, chock full of Wasm tidbits and captivating compiler content.

Not signed up? You're missing out!

Get on the list at sendfox.com/wasmgroundup
Wasm tidbits • All the videos from the WebAssembly Workshop at ICFP/SPLASH '25 are up on YouTube. There are a bunch of interesting ones, but we particularly enjoyed Oscar Spencer's Wasm GC and the Future of High-Level Language Compilation. • The Feature Status page on webassembly.org has been updated to include a bunch of new engines and tools, including Wizard, wazero, and Binaryen. • It's not directly related to WebAssembly, but we've been following Matt Godbolt's Advent of Compiler Optimizations, and it's been great so far. It's a nice way to learn a bit more about x86 and ARM assembly, and about the various optimizations that C++ compilers do. You can follow it on his blog or on YouTube. • Andy Wingo: "If anyone has never worked on a baseline compiler before, they are a really funny space; my first experience with Firefox's Wasm baseline compiler was an eye-opener for me." Firefox's low-latency WebAssembly compiler (2020). • For a deeper look at strategies for baseline compilation, see Ben Titzer's Whose baseline compiler is it anyway?. "We demystify single-pass compilers for Wasm, explaining their internal algorithms and tradeoffs, as well as providing a detailed empirical study of those employed in production." • We recently met some folks from CedarDB (the commercial version of the Umbra database system), who told us about how they use Wasm for user-defined operators. The details can be found in Moritz Sichert's PhD dissertation, Efficient and Safe Integration of User-Defined Operators into Modern Database Systems.
December 18, 2025 at 3:06 PM
Reposted by Patrick Dubroy
ohmjs.org
Just added an example to the Ohm repo of implementing something like Zed's SumTree.

(aka "monoid-cached trees" if you want to sound clever)

Full example here: github.com/ohmjs/ohm/bl...
Screenshot of the following code: // In abstract algebra, a _monoid_ is a set (or a data type) that has // (a) a "combine" operation that's associative, i.e. (a + b) + c = a + (b + c) // (b) an identity or neutral element. // This is our identity element… const LOC_IDENTITY = {line: 0, col: 0}; // …and this is our "combine" operator. function sumLocations(a, b) { return { line: a.line + b.line, // If `b` has more than one line, we can ignore `a.col`. col: b.line > 0 ? b.col : a.col + b.col, }; } function compareLocations(a, b) { return a.line - b.line || a.col - b.col; } const semantics = g.createSemantics(); // A helper operation to get the "size" of a node, such that // endLoc = sumLocations(startLoc, size). semantics.addAttribute('_size', { _default(...children) { return children.reduce((acc, node) => sumLocations(acc, node._size), LOC_IDENTITY); }, _terminal() { const lines = this.sourceString.split('\n'); return { line: lines.length - 1, col: lines.at(-1)?.length || 0, }; }, });
December 10, 2025 at 3:59 PM
Reposted by Patrick Dubroy
wasmgroundup.com
A very readable doc about V8's new bytecode verifier.

Readers of our book may notice the similarity to the Wasm security model — see this excerpt from the chapter "What makes WebAssembly safe?"
Excerpt from the V8 Sandbox - Bytecode Verification doc, reading: "The bytecode verifier needs to ensure that the execution of verified bytecode does not lead to out-of-sandbox corruption, specifically stack corruption. As the bytecode is fairly simple, this reduces down to a few basic properties that must be verified: Spatial memory safety: stores (and potentially loads) to/from the stack stay inside the stack frame and so do not corrupt stack memory Control-flow Integrity (CFI): jumps within the bytecode land at a valid instruction (otherwise, we might execute arbitrary instruction and so the first property could not be guaranteed) No unsafe functions: the bytecode should not call unsafe runtime or native functions These properties are verifiable in linear time (constant per bytecode) with a relatively simple validator." An excerpt from WebAssembly from the Ground Up, showing a section entitled "Sandboxed execution". The excerpt reads: "WebAssembly sandboxed execution is based on a technique known as Software-based Fault Isolation (SFI). It’s a remarkably simple idea. Here’s how it works — The “sandbox” consists of two regions of memory: a code region and a data region. Then, the host must enforce two policies: - A data-access policy ensures that any memory access in the untrusted module can only target its designated data region. - A control-flow policy ensures that the untrusted module can’t transfer control outside its own code region — except by calling explicitly-allowed functions."
December 9, 2025 at 11:13 AM
Reposted by Patrick Dubroy
tomasp.net
What defines a correct program? What education makes a good programmer? The answer depends on what culture of programming you subscribe to!

This has been a long time in the making, but my open access book on the history of programming is available for pre-order!

www.cambridge.org/core/books/c...
December 9, 2025 at 9:52 AM