iiinova — where your digital self keeps evolving

Arthur Pastel @apas.tel · 03/08/2026

CodSpeed v5 is out, with two big changes to how we measure your code. First, cycle estimation: every instruction is now weighted by its measured cost on real CPUs, cache misses included. A `div` no longer counts the same as a `mov`.

CodSpeed v5: Only your code, at its real cost

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Arthur Pastel @apas.tel · 22/07/2026

Frontier models have no runtime performance signal. Not in training data, not as feedback. They can’t measure the code they generate, so they guess. Exciting talk with @heavybit.com about why AI-generated code needs performance guardrails, and what we’re building at @codspeed.io.

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Arthur Pastel @apas.tel · 29/05/2026

"I use it every day and honestly can't live without it. Saves me tons of time." hardfist, lead of @rspack.dev at ByteDance, on the CodSpeed Wizard. So excited to build the performance agent for the fastest projects on the planet!

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Arthur Pastel @apas.tel · 28/05/2026

"If you're gonna ship slop, at least make it fast." Our top sticker at PyCon and there's a reason: code has never been cheaper, reviewers are under pressure and regressions are piling up. Stop thinking about performance, we'll make your thing faster.

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Arthur Pastel @apas.tel · 26/05/2026

Claude Code can now improve performance and fix regressions. The CodSpeed plugin just landed on the official marketplace. Try it out: /𝚙𝚕𝚞𝚐𝚒𝚗 𝚒𝚗𝚜𝚝𝚊𝚕𝚕 𝚌𝚘𝚍𝚜𝚙𝚎𝚎𝚍@𝚌𝚕𝚊𝚞𝚍𝚎-𝚙𝚕𝚞𝚐𝚒𝚗𝚜-𝚘𝚏𝚏𝚒𝚌𝚒𝚊𝚕

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Reposted by Arthur Pastel

Glyph @glyph.im · 17/05/2026

Honorable mention to codspeed.io who, while they do offer some "agentic" stuff, they: 1. also have a robust offering without any AI, and 2. when the "AI" button appeared one day and freaked me out a little bit, I sent an email, and within hours the CEO replied "I understand your concern […]

mastodon.social

Original post on mastodon.social

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Arthur Pastel @apas.tel · 29/10/2025

Excited to have spent some time building this inlining detection. Will come soon with an example use case showing how to leverage this new feature 🤓

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Arthur Pastel @apas.tel · 14/10/2025

Excited to have it out! 🎉 This is just the first step toward adaptive instrumentation: get an overview with wall-time profiling, then zoom in with CPU simulation or other instruments to reach instruction-level detail. This also edges us nearer to real-world sampling in production 👀

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Reposted by Arthur Pastel

EuroRust @eurorust.eu · 05/08/2025

Want to write faster programs? Start with the backbone of performance: the memory allocator Last year, @apas.tel took us deep into an often overlooked topic and made it impossible to forget. Watch it again👇🏼

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Reposted by Arthur Pastel

EuroRust @eurorust.eu · 01/07/2025

What’s faster in Rust? 🦀 Your instinct says one thing. The benchmark says something else. @apas.tel and @adriencaccia.bsky.social are bringing a live Rust performance quiz to #EuroRust25. You don’t want to miss it! 🧵1/3

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Arthur Pastel @apas.tel · 05/06/2025

Announcing p99.chat, the assistant for software performance optimization 🚀 Describe your performance challenge, share your code, and p99 will analyze, instrument, and visualize the results, cutting the traditional setup overhead down to seconds!

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Arthur Pastel @apas.tel · 30/05/2025

We’re at @pyconit.bsky.social with @adriencaccia.bsky.social! We’ll quizz you on Python performance again tomorrow! See you in room lasagna at 11:45!

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Reposted by Arthur Pastel

EuroRust @eurorust.eu · 15/05/2025

🦀 @apas.tel - The Impact of Memory Allocators on Performance Memory allocators are often overlooked. But Arthur makes the case that they’re a key lever for performance in Rust. Learn how they work and when to care. 🧵 5/11 📺 Watch: youtu.be/pJ-FRRB5E84

youtu.be

The Impact of Memory Allocators on Performance: A Deep Dive - Arthur Pastel | EuroRust 2024

YouTube video by EuroRust

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Arthur Pastel @apas.tel · 07/05/2025

We just improved our C++ integration. Now with first-class Bazel support for larger projects! codspeed.io/changelog/20...

codspeed.io

First Class Bazel Support for C++ - Changelog - CodSpeed

New updates and improvements released to Codspeed.

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Arthur Pastel @apas.tel · 27/03/2025

We just released support for C++ benchmarks, enabling the use of our google benchmark compatibility layer to measure the performance of C++ codebases! Learn more: codspeed.io/changelog/20...

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Arthur Pastel @apas.tel · 04/03/2025

Super excited about our latest changes to make performance testing more accessible! Two significant changes: ✅ The Free plan now includes private repositories (up to 5 users) ✅ Macro Runners are now globally available (bare-metal ARM64, 16 cores, 32GB RAM) with 120 min/month included for free

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Arthur Pastel @apas.tel · 28/02/2025

We now support sharded benchmark execution to provide even faster performance feedback!

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Arthur Pastel @apas.tel · 19/02/2025

Single-core performance gains have largely plateaued. That means no more relying on “free” hardware speed boosts. CPUs haven't stopped improving, but we must actively tap into new architectures. Concurrency, SIMD, and thoughtful optimizations can still unlock impressive speedups.

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Arthur Pastel @apas.tel · 17/02/2025

`x * x` generates exactly the same assembly as `x.pow(2)` in Rust and this goes even beyond powers of 2, thanks to LLVM loop unrolling and exponentiation by squaring.

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Hynek Schlawack @hynek.me · 16/02/2025

codspeed.io is pretty cool and class creation will be 38–52% faster in attrs 25.2.0 github.com/python-attrs/attrs/pull/…

CodSpeed showing PR performance improvements between 38% for frozen class to 52% for make_class.

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Arthur Pastel @apas.tel · 13/02/2025

The big issue with such an approach is that the instrumentation is limited to the interpreter itself while for native binary instrumentation the boundary is system calls and only the user space can be instrumented.

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Arthur Pastel @apas.tel · 13/02/2025

We just released a Divan 🛋️ integration. So far, this is the best developer experience you can hope for building performance tests in Rust 🦀! codspeed.io/changelog/20...

codspeed.io

Divan Support for Rust - Changelog - CodSpeed

New updates and improvements released to Codspeed.

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Arthur Pastel @apas.tel · 12/02/2025

Started hacking on a small TUI for managing EC2 instances and SSH connections. Can’t wait to ditch AWS Console's clunkiness.

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Arthur Pastel @apas.tel · 11/02/2025

For languages running on a VM (Python, Java, JS, etc.), performance instrumentation should happen at the VM level. Execution environments vary, but the interpreter is the single source of truth for performance behavior.

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Arthur Pastel @apas.tel · 10/02/2025

Lets go! I’ll be in Pittsburgh again in may for PyCon US 2025! Super excited to try a new interactive talk format this year!

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Arthur Pastel @apas.tel · 17/12/2024

We've just released some new changes, improving the UX for large-scale results display and sharing results when there are many benchmarks! Check out the demos:

codspeed.io

Improvements of the Benchmark and Branch pages - Changelog - CodSpeed

New updates and improvements released to Codspeed.

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Reposted by Arthur Pastel

CodSpeed @codspeed.io · 04/12/2024

Day 3 of the Advent of CodSpeed is done! You can still be a part of it and test your code's performance against the other participants at codspeed.io/advent

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EuroRust @eurorust.eu · 04/12/2024

[Sponsored post] This December, @codspeed.io is hosting an epic Rust Performance Leaderboard for the Advent of Code! 🦀 The fastest solutions win amazing prizes like a MacBook, Nintendo Switch, and more! ➡️ codspeed.io/advent #rust #rustlang #eurorust24 #adventofcode #codspeed #programming

codspeed.io

Advent of CodSpeed - CodSpeed

A performance challenge based on the Advent of Code problems.

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Reposted by Arthur Pastel

CodSpeed @codspeed.io · 02/12/2024

It's a wrap for Day 1 of the Advent of CodSpeed. We saw a lot of interesting optimizations and ideas. Let's continue pushing through this advent month! 🎄

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Arthur Pastel @apas.tel · 29/11/2024

This December, we’re giving away a MacBook Air, a Nintendo Switch, and more! 🎁 Want in? Write the fastest Rust solutions to Advent of Code problems and make it to the top of the leaderboard. codspeed.io/advent

codspeed.io

Advent of CodSpeed - CodSpeed

A performance challenge based on the Advent of Code problems.

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Arthur Pastel @apas.tel · 27/11/2024

We have a new instrument out there!

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Arthur Pastel @apas.tel · 26/11/2024

After so much requests, I'm so excited to have this one out :)

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Arthur Pastel @apas.tel · 25/11/2024

Really excited about this first launch! It's been a long time we wanted to rework the whole app and we're really thrilled to release this!

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Reposted by Arthur Pastel

EuroRust @eurorust.eu · 08/11/2024

A new video! Dive into memory allocation with @art049.bsky.social from @codspeed.bsky.social . Learn why stack, heap, and static memory aren’t all created equal, and how the right choices can boost your Rust app’s performance 🦀 📹👉 youtu.be/pJ-FRRB5E84 #rustlang #performance #memoryallocation

youtu.be

The Impact of Memory Allocators on Performance: A Deep Dive - Arthur Pastel | EuroRust 2024

YouTube video by EuroRust

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