Y Combinator’s CEO says he ships 37,000 lines of AI code per day. A developer looked under the hood

We love a good old social media roast, and Y Combinator CEO Garry Tan found himself on the business end of a doozie Wednesday. 

Tan, who in a past life worked as an engineering manager at Palantir and has more recently been a vocal proponent for AI acceleration, bragged that he and his AI coding agents have been deploying 37,000 lines of code per day across five separate projects. “Absolutely insane week for agentic engineering,” Tan wrote in an X post on Monday, adding in a follow-up post that he was on a 72-day shipping streak.

Two days later, a Polish game developer and senior software engineer who goes by the username Gregorein decided to have a closer look at the actual results of all that shipping by taking a peek at Tan’s AI-focused blog. “Here’s what 78,400 lines of AI slop code actually looks like in production,” Gregorein wrote on X.

Gregorein found these nuggets during his late March review of Tan’s site code and network requests: 

• Tan/AI built the website so that when a user visits, their browser makes 169 server requests for various assets totalling 6.42 megabytes in size. For comparison, the minimalist Hacker News homepage (also run by Y Combinator) makes 7 requests for data totaling just 12 kilobytes.

• The website ships 28 actual test files (code developers use to reality-check their work) straight to every visitor’s browser. That’s 300 KB of pure developer scaffolding that users never asked for.

• It loads 78 different JavaScript controllers for features like AI image generation, voice extraction, video tools, etc., none of which appear on the homepage. The browser still has to download all of them “just in case.”

• The site’s logo is an illustration of a bear. The site downloads the logo in eight different formats, including a completely empty 0-byte file that somehow made it to production, Gregorein found. 

• The website uses huge, uncompressed old-school PNGs (some nearly 2 MB each) even though the browser literally asks for modern tiny formats. Two images alone waste about 4 MB; with newer formats they could have been just 300KB.

• Gregorein also found duplicate page content, an empty CSS (Cascading Style Sheets) file, a huge rich-text editor loaded on a read-only page, missing image descriptions, and analytics code that deliberately routes through a proxy to dodge people’s ad blockers (with a comment in the code admitting it), Gregorein reports.

• Gregorein notes that his review included only the front end code viewable in the browser, not the backend and database code. Even without touching the backend, the public-facing output (the website user experience) makes it clear that the Tan’s website is full of obvious bloat, waste, and rookie mistakes. 

The larger point is that while AI coding tools make it easy to pump out lots of code, it’s really (still) the quality of the code that matters. Quantity, in other words, doesn’t necessarily equal quality. Sure, non-coders can use plain language to direct an AI tool to quickly build websites or apps or new features, but if that code goes into production without proper scrutiny and testing, it can cause obvious functional failures, create security vulnerabilities, or introduce issues that surface later and force engineers to track down and fix the underlying code.

Gregorein isn’t criticizing AI coding tools, or developers’ reliance on them; as he’s pointed out on social media, he uses the tools himself. But he’s saying that the tools are still an enhancement, not a replacement, for skilled software engineering.

Neither Tan nor Gregorein immediately responded to Fast Company’s request for comment. Tan did, however, take to X on Thursday to write: “Good morning haters! Your hate makes me stronger. I love you all.” His post was accompanied by a meme of a laughing Snow White.

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