While it has been 18 months since I blogged about it, the json gem performance has improved quite significantly since, so now is a good time to add a few more parts to my JSON serie: byroot.github.io/ruby/json/20...

Excited to speak at @euruko.org this year, see you in Brno in September! 2026.euruko.org

EURUKO 2026 — European Ruby Conference · Brno

The annual European Ruby Conference. Two days of talks, community, and hallway hacking in Brno, Czech Republic — September 17–18, 2026.

2026.euruko.org

Just shipped my first release of the datadog gem! github.com/DataDog/dd-t...

Release 2.38.0 · DataDog/dd-trace-rb

Added Dynamic Instrumentation: Log probes now support capture expressions as an alternative to capturing the full local/argument scope (#5845) SSI: Add support for Ruby 4.0 runtime (#5981) SSI: Ad...

github.com

concurrent-ruby 1.3.7 is released and fixes 3 security vulnerabilities: github.com/ruby-concurr...

Release v1.3.7 · ruby-concurrency/concurrent-ruby

There are 3 security fixes in this release, so updating is recommended. These security vulnerabilities are not very likely to be hit in practice and have a corresponding Low severity score. What's...

github.com

While his mountain of horrible personal conduct could fill multiple books, one fact in particular stands out: A year ago, Musk’s actions directly led to the deaths of hundreds of thousands of people. He did it knowingly. And, worse — gleefully. Read more: www.theverge.com/tech/949259/...

I realized it has been ~1.5 years since I concluded my series of post on JSON optimization. So I got curious how much faster it became since then. 2.7.2 was the last version before I took over maintainership. 2.9.0 was the version I released at the end of the blog series.

Inlining: the hard parts bernsteinbear.com/blog/inlinin...

You know it's going well when typing 'github' in my browser has www.githubstatus.com as the first suggestion ...

New linear scan register allocator in ZJIT by @tenderlove.dev ! railsatscale.com/2026-05-27-a...

What if Ruby 4.0 features could be implemented in pure Ruby? With TruffleRuby, that’s possible: 73% of the core library is written in Ruby itself. We currently have 10 issues tagged [easy, pure Ruby] waiting for contributors: github.com/truffleruby/...

I installed the Codex extension in VSCode, the result is it corrupts (!) my git repository when using VSCode as the git editor (EDITOR='code -w'). Filed github.com/openai/codex..., was a pain to figure it out.

New take about Ruby C extensions: append_cflags "-Wall" or "-Wextra" with -Werror is a bug waiting to explode as it overrides -Wno-$category flags from RbConfig by being added at the end. It's unnecessary too because for Ruby 1.9+ RbConfig::CONFIG["warnflags"] starts with "-Wall -Wextra"

Flying into RubyKaigi, I thought we had months to stand up AI-assisted vulnerability scanning for rubygems.org. Turns out we were out of time. We started prototyping during the conference, scanned the most critical gems, and four hours later submitted our first advisory to Nokogiri.

Scaling Ruby's defenses with AI

On April 23rd, we submitted a vulnerability report to the Nokogiri maintainers. It was the first one our team has filed using AI-assisted scanning. The maintainers accepted the report and published...

blog.rubygems.org

Not only @github.com search is broken for PRs for 24+ hours but also just the list of PRs misses some PRs entirely. I have to resort to email to even find my own PRs now.

Mustermann 4.0 released! sinatrarb.com/2026/04/27/m...

I have been trying mise (from @jdx.dev) and rbenv recently, the winner is clear: $ time ruby -e0 mise: 51ms rbenv: 152ms 100ms overhead is way too much (due to shims). Additionally: * rbenv breaks `which` which causes tricky problems. * mise can install precompiled Rubies (much faster)

Matz made a AOT compiler for a subset of Ruby: github.com/matz/spinel Great speedups but does not support metaprogramming

GitHub - matz/spinel

Contribute to matz/spinel development by creating an account on GitHub.

github.com

My talk tomorrow is at 14:50 in the #RubyKaigi Large Hall and it now includes 2 demos running at speeds you have never seen before!

TruffleRuby is running Doom at 150 FPS! In @khasinski.bsky.social #RubyKaigi talk "From C to Ruby: Porting Doom"

Great keynote by @headius.bsky.social at #RubyKaigi about JRuby this morning, I enjoyed it

ZRH 🛫 MUC ✈️ HND 🛬 HKD, #RubyKaigi I am on the way. I'm wearing a T-shirt of RubyKaigi 2016, time flies!

C interpreters underlie many of our most widely used language implementations -- but they're slow. Wouldn't it be great if we could turn them into JIT compiling VMs? This video shows what happens when we do just that to the normal Lua VM (first) and "yklua" (Lua w/JIT, second).

TruffleRuby 34 is here 🚀 Full Ruby 3.4 compatibility, up to 23% faster parsing, and a new Prism-based Ripper with 20x speedups! More details in the blog post: truffleruby.dev/blog/truffle...

More than 8 months later, I finally managed to put some thoughts about the passing of my dear friend Piotr into a post. Grief is tough. Remembering Piotr @chastell.net Szotkowski pragtob.wordpress.com/2026/04/12/r...

Remembering Piotr “chastell” Szotkowski

Most of this blog post was written 8 months ago, between his passing and his funeral. I didn’t find the strength to get back to it for a long, long time, but after talking and reminiscing wit…

pragtob.wordpress.com

trivago runs a GraphQL gateway handling 9,000+ req/s per subgraph. After migrating to GraalVM Native Image, they: — eliminated warm-up — reduced replicas from 43 to 12 — cut CPU usage Learn more about their migration process and recommendations: medium.com/graalvm/insi...

Inside trivago’s GraalVM Migration: Native Image for GraphQL at Scale

Introduction

medium.com

I'm starting at Datadog today!

X is a fascist propaganda network by design. It‘s long past time to boycott X. It’s unfathomable no one has even tried to organize a boycott.

Kyle Tharp@kylewilsontharp.bsky.social · 4mo ago

NEW: Data shows out of the top 100 most-viewed X accounts posting about politics in February 2026, 74 were conservative-leaning and 26 were liberal-leaning. 📉 Keep reading for why...

Just received a Most Notable Paper Award for our paper “Cross-language compiler benchmarking: are we fast yet?” published at the Dynamic Languages Symposium 2016. Congratulations to my co-authors @stefan-marr.de and Hanspeter Mössenböck!

GraalWasm just got faster! 🔥 The new threaded interpreter delivers significantly better interpreter performance. In interpreter benchmarks, total execution time is reduced by 5-40%! Details: github.com/oracle/graal...

[GR-69570] Wasm threaded interpreter. by graalvmbot · Pull Request #13181 · oracle/graal

This PR updates the Wasm interpreter to incorporate the recently introduced bytecode handler design (#12825). A detailed documentation of this design can be found at https://github.com/oracle/graal...

github.com

I benchmarked which language works best with Claude Code. Ruby, Python, and JavaScript came out cheapest, fastest, and most stable! See my article in detail: dev.to/mame/which-p...