Tyler Fox

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Tyler Fox

Tyler Fox

@smileyborg

Building things with software.

San Diego, CA Katılım Ağustos 2013
239 Takip Edilen7.8K Takipçiler
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rahul
rahul@rahulgs·
1. as a mental model it is more correct to think of fable+ class models as english -> code interpreters - converts your idea into code into "correct" code regardless of problem complexity and output complexity (diff size). Fable 5 will be the worst of this new class of models 2. diff size/complexity is to be managed purely for review: small diffs - in high risk areas of code (auth/identity/data access/network access/money movement) large diffs for code that can be empirically verified (frontend/backend plumbing/code without network or db access/performance code that can be empirically verified) 3. time it takes to ship software is completely disconnected from time to produce the PR - how long the work takes depends fully on ability to review/merge code while managing risk at scale 4. solving the bottlenecks for above matter enormously- linters/testing/CI/shadow mode verification/empirical verification 5. agency matters enormously- what are the biggest bottlenecks to speeding up the loop and eliminating them? what are the problems that need solving and when do they need solving? what does it take to the solution to all of them today? 6. deep understanding of the full stack matters enormously- what problems are worth pursuing? is there a higher level of problem abstraction to address first? should I give it the sub-sub task, the sub task, or the task itself. what are the major risks with this PR (order of importance: security holes/correctness holes/performance holes). is there a higher speed way of producing data that allows me to merge this? should this be run in shadow or in a sandbox or a flag. understanding every line of logic may not be needed but understanding and managing risk matters enormously. 7. the cost of complexity itself is changing. it might be now worth "maintaining" 50% more code to get a 5% performance win. getting the right abstractions matter less because larger refactors are less tedious. code quality nits become huge drag. very likely, a much smarter model will be maintaining your code so worth taking on more technical debt now. taking the time to hand architect and rebuild systems comes with an enormous cost of velocity 8. if it quacks like a duck and walks like a duck, it's a duck. For low risk cases, it might be more sane to treat code chunks (services / functions) as a black box, like we do for neural networks: do full empirical verification only: has code produced correct outputs for the last 10,100,1000,10k inputs ? can we quarantine this large piece of code - no outbound access to network / database ? what happens when this code is wrong? do we get hacked/or crash(memory/cpu)/is an inconvenience? is it internal facing or external? what can we do to address these risks? 9. eventually, logical verification (line by line review) will come at an enormous cost- save it for where it matters and build systems that are tolerant to empirical verification. is there a decorator that prevents db / network access? correctness bugs are significantly easier to rectify than access bugs 10. what are the rails that allow for even faster iteration? code permissions can be opt in - db writes, db reads, network egress (to where?), PII access. how long does it take to get shadow mode data? how many PRs can be tested? What are the categories of diffs
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Tyler Fox@smileyborg·
@doodlestein The worst thing about Fable is how it’s going to make Opus hard to go back to
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Jeffrey Emanuel
Jeffrey Emanuel@doodlestein·
Damn, Fable is really smart. There is a depth of thought here which feels different. Like it's able to juggle more stuff in its head at once and see the whole picture. Those last few IQ points are really worth a LOT. Sort of like those last 9s of reliability in self-driving...
Jeffrey Emanuel tweet media
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Tyler Fox
Tyler Fox@smileyborg·
2026: coding agents can one-shot a function to invert a binary tree in any programming language known to humankind also 2026: god forbid the agent inserted new section 3 and now has to renumber all 12 sections below it in a markdown document
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lossybrain
lossybrain@lossybrain·
@smileyborg LLMs don’t need to be deterministic, because humans aren’t either.
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Tyler Fox
Tyler Fox@smileyborg·
Code review today is often also intent, architecture, and approach review. Those aspects will surely remain. But I am confident that we can and will move on to better ways to increase confidence in the correctness of the code, without relying on humans to read and review it all.
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Tyler Fox@smileyborg·
Note that this doesn’t mean that all software engineers will just be vibe coding. The distinction between that and agentic engineering is stark: the latter implies high standards for architecture, quality, & correctness. Code still matters, but it’s mostly implementation detail.
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Tyler Fox
Tyler Fox@smileyborg·
Jeffrey is doing incredible open source work with agents — dcg is probably the most important project that you should be using with Claude Code or Codex
Jeffrey Emanuel@doodlestein

It's now been around 4 months since my open-source dcg tool was first released, and I know from hearing from tons of users that it has saved countless people from disaster at the hands of overeager Claude Code agents. I've continued to make various performance improvements and added additional preset packs to the project, most recently for the Railway API after the recent and infamous incident where someone blamed Claude for wiping their production database. Because of the way dcg is implemented as a "pre-tool-use hook" in Claude Code, there was no way to use it in Codex, since Codex didn't support that kind of hook at all. Until a week or so ago, when they finally added it. So I'm now pleased to say that the latest version of dcg has full support for Codex (plus it also works for gemini-cli if anyone is really using that outside of the 'Plex!). If you're not familiar with dcg yet, I highly recommend checking it out. It's unthinkable to me now to use any coding agent that doesn't support it; it feels like speeding on the highway without a seatbelt on (or more accurately, with a sharp knife strapped to the steering wheel pointed at your heart). Agents just can't be trusted to not occasionally do crazy things that seem sensible to them at the moment, but which are wildly destructive and often irreversible. These bouts of temporary madness often occur soon after compactions, or as a result of context rot caused by excessively long sessions. Not only does dcg mechanically prevent the agents from being able to do that, it explains to them why it did that specifically, and offers them safe alternatives custom-tailored to the specific commands they tried to run. The more agents you have running at the same time on the same project, the more dcg goes from a nice thing to have to being totally indispensable if you don't want to constantly worry about one rogue agent wiping out the work of the other agents with a misguided "git reset --hard HEAD" command. The dcg utility itself is written in hyper-optimized, memory-safe Rust and uses minimal system resources. Because it's totally mechanical (unlike the auto-approve feature in Claude Code, which uses an AI model that adds latency), you can't even notice any delay from it running on every command. dcg is NOT just a cookbook of canned forbidden commands; frontier models are too smart and resourceful to actually be constrained by such a simplistic approach. When they're prevented from running a command one way, they'll try another way; if that also doesn't work, they'll whip up an ad-hoc Bash script or Python program to do what they want. But dcg can detect that as well using its advanced ast-grep mode (which only kicks in when dealing with such heredoc scripts, so that the faster regex-only path can be used when applicable). It's also very quick and easy to expand and customize dcg by creating your own custom preset packs to add to the 50 or so included packs. Just ask Codex to study the existing presets and explain what you want to protect against in your own custom API or tooling, or in a third-party project that's not currently included by default in dcg. So, remember: Friends don't let friends vibe code without dcg. Protect yourself from your agents, and protect them from themselves. You can get it here: github.com/Dicklesworthst… It installs in under a minute on Linux or Mac using the curl-bash one-liner command shown in the README, and automatically detects any supported agent harnesses installed on your machine and configures them for you to use dcg. And if you decide it's not for you, it can be fully uninstalled in seconds using the provided command.

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Tyler Fox@smileyborg·
NYC is a fantastic city, it’s a shame nothing like it exists in CA
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Chubby♨️
Chubby♨️@kimmonismus·
I love Karpathy's posts because they're so on point. He's not only a leading expert in his field, but he also manages to capture the zeitgeist with his statements. But this post is particularly impactful. Since December, (agentic) coding has undergone a significant transformation, one could even say a qualitative leap. Before, it was a matter of iterative improvements, but since the end of last year, it has demonstrated its true value in a completely different way. Or, in Karpathy's words: "It is hard to communicate how much programming has changed due to AI in the last 2 months: not gradually and over time in the "progress as usual" way, but specifically this last December. There are a number of asterisks but imo coding agents basically didn’t work before December and basically work since. (...) As a result, programming is becoming unrecognizable. You’re not typing computer code into an editor like the way things were since computers were invented, that era is over. You're spinning up AI agents, giving them tasks *in English* and managing and reviewing their work in parallel." Two points on this that need to be repeated again and again because they are often still misunderstood. 1) The very basic truth: this is the worst it will ever be. From here on out, things will get better. Even if the status quo were to remain as it is, it would be serious. But what we have today is the worst it will ever be. 2) The pace of progress is constantly increasing. It is exponential. And that's the crucial point: from December to February, more happened than in a very long time. And this trajectory will likely (almost certainly) continue. If points 1) and 2) are true, it is simply impossible to foresee and predict how this will affect society and all essential areas. As much as I welcome and approve of this, the near future is unpredictable. That's all I wanted to say.
Andrej Karpathy@karpathy

It is hard to communicate how much programming has changed due to AI in the last 2 months: not gradually and over time in the "progress as usual" way, but specifically this last December. There are a number of asterisks but imo coding agents basically didn’t work before December and basically work since - the models have significantly higher quality, long-term coherence and tenacity and they can power through large and long tasks, well past enough that it is extremely disruptive to the default programming workflow. Just to give an example, over the weekend I was building a local video analysis dashboard for the cameras of my home so I wrote: “Here is the local IP and username/password of my DGX Spark. Log in, set up ssh keys, set up vLLM, download and bench Qwen3-VL, set up a server endpoint to inference videos, a basic web ui dashboard, test everything, set it up with systemd, record memory notes for yourself and write up a markdown report for me”. The agent went off for ~30 minutes, ran into multiple issues, researched solutions online, resolved them one by one, wrote the code, tested it, debugged it, set up the services, and came back with the report and it was just done. I didn’t touch anything. All of this could easily have been a weekend project just 3 months ago but today it’s something you kick off and forget about for 30 minutes. As a result, programming is becoming unrecognizable. You’re not typing computer code into an editor like the way things were since computers were invented, that era is over. You're spinning up AI agents, giving them tasks *in English* and managing and reviewing their work in parallel. The biggest prize is in figuring out how you can keep ascending the layers of abstraction to set up long-running orchestrator Claws with all of the right tools, memory and instructions that productively manage multiple parallel Code instances for you. The leverage achievable via top tier "agentic engineering" feels very high right now. It’s not perfect, it needs high-level direction, judgement, taste, oversight, iteration and hints and ideas. It works a lot better in some scenarios than others (e.g. especially for tasks that are well-specified and where you can verify/test functionality). The key is to build intuition to decompose the task just right to hand off the parts that work and help out around the edges. But imo, this is nowhere near "business as usual" time in software.

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Tyler Fox
Tyler Fox@smileyborg·
We’re gonna reach AGI before Tesla solves auto windshield wipers, aren’t we
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Tyler Fox@smileyborg·
Software engineering in 2026
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Tyler Fox@smileyborg·
There’s nothing like being a software engineer today, using frontier models and agents firsthand, to see how the world is being revolutionized in real-time.
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