Krzysztof Cieslak

Krzysztof Cieslak

@kcieslak.io

Artist 🎨 | Photographer 📷 | Globetrotter 🌍 | Speaker 🤹🏻‍♂️ | Author of Ionide 🚀 | Researcher @ Github Next 🔬| Co-creator of GitHub Copilot, Copilot NES, Agentic Workflows, and Ace | Building the future of software development 💻

1.8K followers122 following782 posts

It’s sad that this is way better platform and yet Twitter is still, after all this year, better place for talking about software development and AI

Introducing my new side project - Fai. github.com/Krzysztof-Ci... It’s a functional programming language with which I try to explore how we can design better “classical” software engineering tools specifically for AI agents. A couple of design choices I've made are described ⬇️

github.comGitHub - Krzysztof-Cieslak/fai: Programming language for AI ageProgramming language for AI age . Contribute to Krzysztof-Cieslak/fai development by creating an account on GitHub.
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... All this is possible thanks to the design of the compiler from the ground up to be incremental and adaptive, the use of parallel compilation, the content-addressed caching, and using the compiler as a long-running daemon rather than a batch-mode tool.

* Finally, we focus a lot on the predictable performance of the generated code. Automatic memory management using Perceus-style reference counting allows a whole set of optimizations not seen in most programming languages, while keeping FP semantics.

Introducing my new side project - Fai. github.com/Krzysztof-Ci... It’s a functional programming language with which I try to explore how we can design better “classical” software engineering tools specifically for AI agents. A couple of design choices I've made are described ⬇️

github.comGitHub - Krzysztof-Cieslak/fai: Programming language for AI ageProgramming language for AI age . Contribute to Krzysztof-Cieslak/fai development by creating an account on GitHub.
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* Ability to iterate quickly and improve based on tool invocation results is one of the AI agents superpowers. To maximize this, I focused on making sure Fai tooling and compiler are as fast as possible (yes, I’m looking at you, Rust)…

… Fai programs can compile, provide tooling-based information, and run in milliseconds, and we make sure their compilation time and typechecking time don't grow based on the size of the project but only based on the size of the edit done since the last compilation...

Introducing my new side project - Fai. github.com/Krzysztof-Ci... It’s a functional programming language with which I try to explore how we can design better “classical” software engineering tools specifically for AI agents. A couple of design choices I've made are described ⬇️

github.comGitHub - Krzysztof-Cieslak/fai: Programming language for AI ageProgramming language for AI age . Contribute to Krzysztof-Cieslak/fai development by creating an account on GitHub.
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* Those languages are well known for strong type systems - lack of nulls, exhaustive pattern matching, algebraic data types, all of which allow making illegal states irrepresentable. Fai builds, moreover, adding a capabilities system to make language pure and easy to reason about

* Expanding on the correctness - Fai adds unit tests and property-based tests as first-class features of the language. `example` and `forall` blocks live next to functions, not as documentation but as a normal code block, type checked and compiled together with your code.

Introducing my new side project - Fai. github.com/Krzysztof-Ci... It’s a functional programming language with which I try to explore how we can design better “classical” software engineering tools specifically for AI agents. A couple of design choices I've made are described ⬇️

github.comGitHub - Krzysztof-Cieslak/fai: Programming language for AI ageProgramming language for AI age . Contribute to Krzysztof-Cieslak/fai development by creating an account on GitHub.

TLDR: Fai thanks to the combination of features, and the compiler design focuses on development using AI agents * Correctness and reasonability about generated code * Tooling performance enabling faster iteration * Generated code performance and innovative memory management 🧵⬇️

* Fai is a statically typed, functional programming language from the ML family, heavily influenced by languages like F#, Elm, or Koka. Thanks to simple syntax and high expressiveness, such languages are shown to have way higher token efficiency than most mainstream languages.

Krzysztof Cieslak reposted

I hate screenshot culture so fucking much. If you repost some rando’s unsourced screenshot of a graph because it’s vaguely professional-looking and supports some idea you want to believe, then idk, you might not be a bad person, but you’re definitely making the world a worse place.

So Ultrafast has broken my workflow - I used to run 2-3 agents in parallel (often on separate projects/explorations) even in "plan mode". Ultrafast is so fast that I can't context switch; I need to focus just on a single agent. This is great. I love it

I think the only thing stopping me from using iPad as main travel-conference machine is lack of support for custom fonts in keynote. And well, worry about projector compatibility

“Invented on social media”. Clearly among the 95%

wariziles@riziles.bsky.social

I'd go so far as to say that 95% of America doesn't understand the distinction between liberal and leftist we invented on social media

On the one hand Warsaw is not really city which vibe I enjoy… But I’m kinda glad this view exists as it’s great symbol for the last 20 years of growth

I’m not surprised that all we see are just silly demos - coming up with unique new ideas is hard and most developers are not really great at it. 🤷 Also innovation takes time, just because we’ve got new model like 5 days ago doesn’t mean everyone already had all the good ideas

Gergely Orosz@gergely.pragmaticengineer.com

So no, I'm not particularly excited about Fable 5.1 or Astra or anything else - what would I use it for?? The fact that Astra demos are all about recreating old games in web browsers suggests to me people also have no idea what to use these new models for save for copying existing software tbh

iPad + Magic Keyboard + ssh is kinda good dev setup nowadays. I’m just sitting at cafe, switching between 5 different ssh sessions and managing agents 😂

Astra is great. Sol was great. Whatever was before was great. The real breakthrough would Astra (or even Sol) quality model that's 100x faster than current models. It would open completely new user experiences, and handle completely new use cases.

Ofc, labs will never go for it - current AI race reminds me early digital camera competition. Number of megapixels is most important! Even if it actually doesn't bring quality up, degrades low light performance, etc So instead of getting faster models we will get more benchmark-maxxing

Black uniforms with SW Empire vibe. LMAO, they're not even pretending, do they.

derek guy@dieworkwear.bsky.social

this is the kind of design costume designers make to tell you who are the bad guys in a space movie

Computer use is architecturally terrifying and is disgusting way of using agents. But it just shows how bad were foundations we've been building software on for all those years - lack of compossibility, programmable APIs and walled gardens just came back to hunt us.

I’d be more worried about any software whose team is not using AI nowadays*. It would suggest level of… closed-mindedness that doesn’t leads to good end-user software * yes, there are some counter-examples, but 99,99% of software doesn’t control nuclear reactors or planes or medical equipment.

This post is unavailable.

I would never share this.

Patton Oswalt@pattonoswalt.bsky.social

Apparently people are sharing this far and wide on social media, which I think is horrible. This could cripple ICE operations. PLEASE do not share this.

Finally playing with the Pi. I have no idea if the setup I create will be better than what I used before (OpenCode). But at least I have fun putting different pieces together. Reminds me of old-school editor hacking.

I find this reporting absolutely shocking - finance.yahoo.com/technology/a... Not the $28k value, this one seems OK. The shocking part is this: > Among roughly 350 employees who completed the tracker, median AI spending was about $300 in the same 28 days.

finance.yahoo.comMicrosoft employee spends $28,000 on AI tokens in 28 days, internal tracker showsCompanies have spent years urging workers to use AI more frequently, only to run into the financial consequences.

Krzysztof Cieslak reposted

Can we form like a pro ai sane left of center progressive faction or what

I’m building something new, and as y’all know I love building OSS. 🚀 Check out blog post for our vision for multiplayer, ai-first document-focused environment. And also check out the code base if you’d want to use it today! (Links in quoted thread 🧵)

GitHub Next@githubnext.com

New project from GitHub Next! Chopin is a real-time, multiplayer, agentic planning environment designed to align your team. Our current planning tools feel static, lonely, and drown us in walls of text. How can we make planning feel interactive, shared, and visual? githubnext.com/projects/cho...