[saberience]

I'm writing low-level Rust, distributed systems, also sandboxing tech which has to be secure and performant.

The only thing I have Fable do now is create UIs or otherwise front-ends for systems where correctness doesn't matter as much.

Anthropic models lead at making nice looking UIs for sure, but when it comes to making sure my Rust code is actually 100% correct and uses 1% of CPU most of the time, Codex is king.

[felixgallo]

definitely not in my experience. I usually write distributed systems and back end code, and Fable is so much better at those than Codex that it's not even a comparison. Fable feels like it's a year ahead.

[saberience]

Interesting, I’d love to see the comparisons of your system using Claude vs Codex. I have about 20 years of experience in distributed systems and super high scale at several faangs, and also building ai model serving infra for 20k transactions per second roughly.

For me, Claude makes bone headed decisions all the time, like glaring errors, not even particularly subtle.

But the more obvious flag is the amount of irrelevant code and tests which Fable writes. Like it regularly writes 2X or 3X the amount of code and tests that are needed. It’s an expert at writing plausible but entirely useless tests.

But I think that if you’re a more junior engineer or haven’t been around a the block you can easily think that “more code equals smarter”. Claude ends up creating a massive, hard to manage codebase, and if you look the Claude Code codebase (which was leaked), you can see I’m right!

The Claude Code codebase is terrible. And presumably Anthropic has been using their smartest models for working on Claude Code. I wrote my own coding harness with Codex (as a fun experiment) which used a fraction of the code and is about 100X more performant and memory efficient (than Claude Code)!

[felixgallo]

I have over 40 years of experience in distributed systems, ranging from fintech to games like Call of Duty, and I owned several key APIs in the Alexa pipeline for many years, so I'm pretty sure I'm not a more junior engineer or haven't been around the block. Good effort though!

Fable does make mistakes, but GPT and Opus were L4 SDEs, and Fable is a freshly promoted L5 SDE. It's not perfect and does need babysitting, especially where the literature is thin, but it's head and shoulders on top right now. That could change, who knows.

As far as driveby attacks on Claude Code The App go, you can say that, but you will also note that Claude Code is the AWS-like clear dominant favorite as a dev tool at the moment, with Codex and Gemini battling for scraps. In the same manner that Excel (which, internally, is total garbage from a code quality/cleanliness perspective) is the winner in spreadsheets, and Word (which, internally, is total garbage from a code quality/cleanliness perspective), and JavaScript (total garbage from a language design perspective), and Facebook (total garbage internally, etc.), and IPv4 (total, etc., etc.), Claude Code has focused on 'delivering amazing things people like' rather than 'making people who get access to the code delighted by the purity and cleanliness of the development process'.

It turns out that being 'delighted by the purity and cleanliness of the development process' rounds to essentially zero in terms of the entire product lifecycle. You could argue that poorly structured codebases are less extensible, and more bug prone, which could be expensive long term. Except, the economics of AI development are quite a bit different than what you are used to, and what our axioms of quality have been founded upon in the past.

Congratulations on writing your own much better coding harness, though! How many MAU do you have?