Visiting Partner @ycombinator, helping founders build iconic startups. Swiss designer, MIT engineer, founder Cron (acq by Notion). I run through forests.
Joined July 2008
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4 Sep 2025
Life update: I'm joining @ycombinator as Visiting Partner 🤩
Software ate the world, and now AI is eating software — the founders building in this shift will redefine how we compute, work, and live.
In my new role, I'm excited to find those founders and help them build the iconic startups of this generation. YC backed me when I founded Cron Inc. in 2019, and I'm grateful to come full circle and pay it forward.
I'll start reading applications in October, interviewing founders in November, and then pack my battered suitcase in January for the W26 batch 🔥
Follow along here & see you in SF!
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Jun 11
I’ve always felt that abundance makes excellence relatively rarer.
Today I figured out why exactly.
And it’s not doomer news, because it makes excellence also more likely:
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Jun 11
Interesting consumer app, building on top of the camera roll. Well designed, too.
I always believed the billions of camera rolls are an incredible data mine: people, location, interests, trips, docs, …
Jun 11
Introducing Pool
That little icon got us $2M in funding, 15M organic views, and now you can all finally discover what's behind it.
Pool is "just an app for your screenshots." But it holds a few bets we decided to build a whole company on.
We believe the context of the future is your camera roll. Understanding someone's taste, the texture of their life, can unlock things we can't even comprehend yet.
We believe the future of interfaces will feel the way games make us feel, computing as a beautiful mix of art and technology.
Now live on the App Store.
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Jun 11
! Paging all Designers who are in SF week of Config ♡
If we were to put up a YC Ă— Designers event, when would be best?
Reply what time … (Breakfast? Happy Hour? Later night?)
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Thu June 25
12 votes • Final results
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Jun 9
Go Knicks! đź—˝
I don't even follow Basketball nor have a TV lol but the excitement here is contagious.
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Jun 8
What do you think about this effect to reveal additional info?
Found it interesting. Sharing some micro UX thoughts in-thread …
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Jun 8
Don't love the underline on hover. Underline in a browser pretty strictly indicates link to me. But it's not clickable, so the affordance feels off.
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Jun 8
Missed opportunity to use a different mouse cursor on hover. Currently using the standard, but could show the browser-built-in question mark cursor? Can sometimes feel a bit heavy but it maps pretty directly to "hover to discover additional information."
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Jun 8
Ok, first “woah” (although simple), Apple flexing platform advantage:
Ask Siri what’s on screen (from any app). Siri AI pops out of notch and helps right there with context what’s going on on phone.
You know how many times I have taken screenshots to upload to ChatGPT/Claude?
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Raphael Schaad retweeted
Here’s your monthly reminder that you shouldn’t be prompting coding agents anymore.
You should be designing loops that prompt your agents.
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Raphael Schaad retweeted
Jun 6
When execution is cheap, design and creativity are the edge.
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Raphael Schaad retweeted
Jun 5
We're excited to announce Peter Steinberger as a speaker at Startup School 2026!
@steipete is the creator of OpenClaw, the open-source AI agent that went from a weekend project to the most-starred software repo on GitHub in under 5 months, with 346k stars. He's now at OpenAI building the next generation of personal AI agents.
ycombinator.com/startupschoo…
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Jun 4
Having a good day?
How about now?
How about now:
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Jun 3
> be Steijn
> go to dentist for checkup
> mortified how lowtech backoffice runs
> take 9-5 job at dentist (leave sweet gig at Robinhood)
> spend 1yr to become domexp
> take learnings & team up with my buddy @fredericrenken
> build AI-powered backoffice for clinics
> raise ~50M from top investors (excited to be small part of it ✌️)
> world domination
Jun 3
Today, we're introducing Lassie and $47M in funding led by a16z.
We're building AI that runs small businesses, starting with doctors' offices.
Lassie is already trusted by 700 practices across the country, working autonomously to provide them with 30 hours of labor per month.
To get here, we first had to leave Robinhood and Superhuman to work in offices ourselves.
Here's how that went.
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Jun 2
Startup investing is the only type of investing where "the investment" needs to pick you back.
Some investors tend to forget.
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