Mar 6, 2026 · 37m · y-combinator
Common Mistakes With Vibe Coded Websites · Y Combinator
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gold bands on the timeline = statements, start to end. Hover to read, click to jump. CC turns on captions
Y Combinator's Aaron Epstein and Raphaël Schaad review AI-built startup landing pages to highlight common AI design tropes, user experience pitfalls, and actionable strategies for founders to create distinct, high-converting websites.
How this conversation actually went
Every chapter scored 0–10 on four independent dynamics. Hover any point for the reasoning behind the score. How this is scored →
The partners as informed peer 6.5 Guest teaching 6.3 Guest disagreement 0.0 The partners pushing back 0.0
speaking balance: gold is the partners, purple is the guest (3 minute bins)
Sharpest disagreement ▶ 7:03 Calling out desktop hover anti-patterns
In a completely collaborative episode, this represents the strongest aesthetic objection as Rafael forcefully rejects hiding critical tools behind hover interactions.
Hardest push from the partners ▶ 21:20 Challenging confusing workflow animationsAaron firmly questions the value of auto-shifting buttons and looping workflow animations that distract from communicating product value.
Biggest teaching moment ▶ 5:46 Browser defaults versus LLM hover mistakesRafael breaks down how native cursor affordances work and why LLM-generated fading hover effects violate foundational UX principles.
The partners hold their own ▶ 35:55 Framework for intentional AI designAaron articulates a clear strategy for founders to define their visual brand and QA rigorously rather than passively accepting LLM defaults.
the scores for every segment, with the reasoning behind each
| Chapter | Topic | The partners as informed peer | Guest teaching | Guest disagreement | The partners pushing back | Why |
|---|---|---|---|---|---|---|
| Title Sequence: Design Review | 6 | 5 | 0 | 0 | Aaron introduces Rafael and discusses the rise of AI design trends and boilerplate tropes like purple gradients and fade-in scroll sections. Both speakers are completely aligned and build on each other's observations. | |
| Website Review: Nunu.ai | 7 | 7 | 0 | 0 | Reviewing Nunu.ai, Rafael breaks down why certain hover animations and hiding critical functionality behind hover are severe anti-patterns on web and mobile. Aaron provides complementary insights on usability and visual distraction. | |
| Website Review: Rosebud AI | 6 | 6 | 0 | 0 | The hosts evaluate Rosebud AI, praising the interactive embedded 3D game sandbox while noting weak hierarchy and clashing color accents. Both agree on core conversion fundamentals like H1 clarity above the fold. | |
| Website Review: GetCrux | 6 | 6 | 0 | 0 | Reviewing GetCrux, both critique distracting scroll-jacking, low-resolution video assets, and delayed fade-in animations that obscure FAQ answers. The tone is constructive and analytical. | |
| Website Review: Sphinx | 7 | 7 | 0 | 0 | Looking at Sphinx, Rafael details how LLMs generate cluttered visual hierarchies with too many conflicting styles and fake interactive buttons. Aaron observes that founders must act as discerning editors rather than blindly accepting AI output. | |
| Website Review: Build0 | 7 | 6 | 0 | 0 | Reviewing Build0, Aaron identifies stereotypical LLM dashboard color tropes (Fisher-Price primaries) while Rafael points out subtle layout shifting bugs caused by careless hover effects. | |
| Website Review: Zarna | 6 | 6 | 0 | 0 | The hosts inspect Zarna, noting severe contrast issues where light header text becomes unreadable over dynamic video backgrounds, alongside non-functional interactive cards. | |
| General Takeaways and Best Practices | 7 | 7 | 0 | 0 | Aaron and Rafael synthesize their key takeaways, stressing that founders must thoroughly QA vibe-coded websites and define their brand identity proactively rather than accepting generic AI defaults. |
Statements from this episode (11)
Epstein: Ubiquity Strips AI Design Tropes of Originality and Impact
“It's not purple gradients are bad. Nobody should ever use them. It's that now they're just so ubiquitous everywhere that they kind of lose all meaning and specialness and originality.”
Schaad: LLMs Rapidly Accelerate Web Design Copycatting and Homogeneity
“When there was a good website kind of establishing a trend, it took a while in the old world for others to kind of like copy these trends. But now with LLMs, if there's a good website with a purple gradient, it makes it into the LLM because the LLM gets traine…”
Epstein: Poor demo design signals a YC applicant didn't try
“Especially as we're reviewing YC applications, if you look at a demo and that demo does not have a base level of quality design, it seems like the person just didn't even try because it's so easy to do it now.”
Schaad: Standard emojis on landing pages are an immediate AI tell
“Whenever I see the use of emojis, even though they're not the system emojis, I feel like it's a little lazy. And so I feel like LLMs kind of take the easy path because they don't have any IP really themselves. They're just like big models kind of cobbling thin…”
Schaad: Scroll-jacking landing pages breaks user orientation and progress tracking
“It's also if these, with these landing pages that kind of, like, build up and then keep you in a section for a little while, it's really hard to know when you're, like, how far into the book you have read. Right? Like, if you have a physical book, you're kind …”
Schaad: One-shotting websites with AI causes founders to overlook interface bugs
“I almost wonder, like if you just one shot landing pages do you actually go and really like use it with the same
Attention detail as you feel if you had like built it from scratch.
And then because you don't you just ship things that are, that you wouldn't hav…”
Epstein: Generic AI website designs undermine startup product credibility
“And for any, anybody else in the audience, like, you lose a little bit of credibility, I think, you know, when your customers are viewing your product and they're saying like,
Eh, this looks like a bunch of other things I've seen.
They probably just use AI to …”
Epstein: Blanket '10x' startup landing page metrics feel fabricated
“It's all, everything 10 x just feels made up.”
Epstein: AI tools generate gratuitous motion effects humans wouldn't build
“Even the little bits of motion here is the kind of thing that like AI will just give you that for free and you're like, yeah, okay, let's go with that. But you would never create yourself.”
Schaad: Startup landing pages must be customer acquisition channels, not interactive toys
“It's kind of like a customer acquisition channel, right? This is not your product. This is not a web site as in kind of like a cool thing on the web. There's space for that as well, but these are like Startup landing pages and they're basically customer acquis…”
Epstein: Founders should define branding before prompting AI web design tools
“It's very easy using the same tools that everybody else is using to end up in the same place. You have to be intentional about ending up in a different place. And so rather than start from What does the AI spit out? And then let's tweak that. I would start fro…”